diff --git a/cmd/dev/stevents/main.go b/cmd/dev/stevents/main.go
index b723ab542..405c34a9d 100644
--- a/cmd/dev/stevents/main.go
+++ b/cmd/dev/stevents/main.go
@@ -17,10 +17,10 @@ import (
 )
 
 type event struct {
-	ID   int                    `json:"id"`
-	Type string                 `json:"type"`
-	Time time.Time              `json:"time"`
-	Data map[string]interface{} `json:"data"`
+	ID   int            `json:"id"`
+	Type string         `json:"type"`
+	Time time.Time      `json:"time"`
+	Data map[string]any `json:"data"`
 }
 
 func main() {
diff --git a/cmd/dev/stfinddevice/main.go b/cmd/dev/stfinddevice/main.go
index f6e94a3ba..cc79927bb 100644
--- a/cmd/dev/stfinddevice/main.go
+++ b/cmd/dev/stfinddevice/main.go
@@ -60,7 +60,6 @@ func checkServers(deviceID protocol.DeviceID, servers ...string) {
 	t0 := time.Now()
 	resc := make(chan checkResult)
 	for _, srv := range servers {
-		srv := srv
 		go func() {
 			res := checkServer(deviceID, srv)
 			res.server = srv
diff --git a/cmd/dev/stgenfiles/main.go b/cmd/dev/stgenfiles/main.go
index eea488b42..1cbbea3d4 100644
--- a/cmd/dev/stgenfiles/main.go
+++ b/cmd/dev/stgenfiles/main.go
@@ -34,7 +34,7 @@ func generateFiles(dir string, files, maxexp int, srcname string) error {
 		return err
 	}
 
-	for i := 0; i < files; i++ {
+	for range files {
 		n := randomName()
 
 		if rand.Float64() < 0.05 {
@@ -51,10 +51,7 @@ func generateFiles(dir string, files, maxexp int, srcname string) error {
 		p1 := filepath.Join(p0, n)
 
 		s := int64(1 << uint(rand.Intn(maxexp)))
-		a := int64(128 * 1024)
-		if a > s {
-			a = s
-		}
+		a := min(int64(128*1024), s)
 		s += rand.Int63n(a)
 
 		if err := generateOneFile(fd, p1, s); err != nil {
diff --git a/cmd/dev/stvanity/main.go b/cmd/dev/stvanity/main.go
index 12b2e8bda..0154de5d0 100644
--- a/cmd/dev/stvanity/main.go
+++ b/cmd/dev/stvanity/main.go
@@ -138,7 +138,7 @@ func printProgress(prefix string, count *atomic.Int64) {
 	}
 }
 
-func saveCert(priv interface{}, derBytes []byte) {
+func saveCert(priv any, derBytes []byte) {
 	certOut, err := os.Create("cert.pem")
 	if err != nil {
 		fmt.Println(err)
@@ -179,7 +179,7 @@ func saveCert(priv interface{}, derBytes []byte) {
 	}
 }
 
-func pemBlockForKey(priv interface{}) (*pem.Block, error) {
+func pemBlockForKey(priv any) (*pem.Block, error) {
 	switch k := priv.(type) {
 	case *rsa.PrivateKey:
 		return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}, nil
diff --git a/cmd/infra/stcrashreceiver/main.go b/cmd/infra/stcrashreceiver/main.go
index 54356f81f..4d73b7253 100644
--- a/cmd/infra/stcrashreceiver/main.go
+++ b/cmd/infra/stcrashreceiver/main.go
@@ -203,7 +203,7 @@ func loadIgnorePatterns(path string) (*ignorePatterns, error) {
 	}
 
 	var patterns []*regexp.Regexp
-	for _, line := range strings.Split(string(bs), "\n") {
+	for line := range strings.SplitSeq(string(bs), "\n") {
 		line = strings.TrimSpace(line)
 		if line == "" {
 			continue
diff --git a/cmd/infra/strelaypoolsrv/auto/noassets.go b/cmd/infra/strelaypoolsrv/auto/noassets.go
index 9251e08e0..6ae86d063 100644
--- a/cmd/infra/strelaypoolsrv/auto/noassets.go
+++ b/cmd/infra/strelaypoolsrv/auto/noassets.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build noassets
-// +build noassets
 
 package auto
 
diff --git a/cmd/infra/strelaypoolsrv/main.go b/cmd/infra/strelaypoolsrv/main.go
index 2bd5ba4da..bd3604b2c 100644
--- a/cmd/infra/strelaypoolsrv/main.go
+++ b/cmd/infra/strelaypoolsrv/main.go
@@ -587,7 +587,7 @@ func loadRelays(file string, geoip *geoip.Provider) []*relay {
 	}
 
 	var relays []*relay
-	for _, line := range strings.Split(string(content), "\n") {
+	for line := range strings.SplitSeq(string(content), "\n") {
 		if line == "" {
 			continue
 		}
diff --git a/cmd/infra/strelaypoolsrv/main_test.go b/cmd/infra/strelaypoolsrv/main_test.go
index 7c8520f14..a76f304f4 100644
--- a/cmd/infra/strelaypoolsrv/main_test.go
+++ b/cmd/infra/strelaypoolsrv/main_test.go
@@ -17,7 +17,7 @@ import (
 )
 
 func init() {
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		u := fmt.Sprintf("permanent%d", i)
 		permanentRelays = append(permanentRelays, &relay{URL: u})
 	}
diff --git a/cmd/infra/stupgrades/main.go b/cmd/infra/stupgrades/main.go
index 8bdb73bf3..76daee578 100644
--- a/cmd/infra/stupgrades/main.go
+++ b/cmd/infra/stupgrades/main.go
@@ -188,7 +188,7 @@ func (p *proxy) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	w.WriteHeader(resp.StatusCode)
 	if strings.HasPrefix(ct, "application/json") {
 		// Special JSON handling; clean it up a bit.
-		var v interface{}
+		var v any
 		if err := json.NewDecoder(resp.Body).Decode(&v); err != nil {
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
diff --git a/cmd/stdiscosrv/apisrv.go b/cmd/stdiscosrv/apisrv.go
index 7c486669c..565206ca1 100644
--- a/cmd/stdiscosrv/apisrv.go
+++ b/cmd/stdiscosrv/apisrv.go
@@ -402,10 +402,7 @@ func (s *apiSrv) certificateBytes(req *http.Request) ([]byte, error) {
 		b.WriteByte('\n')
 
 		for i := 0; i < len(cert); i += 64 {
-			end := i + 64
-			if end > len(cert) {
-				end = len(cert)
-			}
+			end := min(i+64, len(cert))
 			b.WriteString(cert[i:end])
 			b.WriteByte('\n')
 		}
diff --git a/cmd/stdiscosrv/apisrv_test.go b/cmd/stdiscosrv/apisrv_test.go
index 54ea74ecd..21864c073 100644
--- a/cmd/stdiscosrv/apisrv_test.go
+++ b/cmd/stdiscosrv/apisrv_test.go
@@ -7,7 +7,6 @@
 package main
 
 import (
-	"context"
 	"crypto/tls"
 	"fmt"
 	"io"
@@ -120,7 +119,7 @@ func TestRetryAfterSHistogram(t *testing.T) {
 	numBuckets := (notFoundRetryUnknownMaxSeconds + bucketSize - 1) / bucketSize
 	buckets := make([]int, numBuckets)
 
-	for i := 0; i < n; i++ {
+	for range n {
 		v := tracker.retryAfterS()
 		if v < notFoundRetryUnknownMinSeconds || v > notFoundRetryUnknownMaxSeconds {
 			t.Fatalf("retryAfterS() = %d, out of range [%d, %d]", v, notFoundRetryUnknownMinSeconds, notFoundRetryUnknownMaxSeconds)
@@ -142,10 +141,7 @@ func TestRetryAfterSHistogram(t *testing.T) {
 	barWidth := 60
 	for i, c := range buckets {
 		lo := i*bucketSize + 1
-		hi := (i + 1) * bucketSize
-		if hi > notFoundRetryUnknownMaxSeconds {
-			hi = notFoundRetryUnknownMaxSeconds
-		}
+		hi := min((i+1)*bucketSize, notFoundRetryUnknownMaxSeconds)
 		bar := ""
 		if maxCount > 0 {
 			bar = strings.Repeat("#", c*barWidth/maxCount)
@@ -156,8 +152,7 @@ func TestRetryAfterSHistogram(t *testing.T) {
 
 func BenchmarkAPIRequests(b *testing.B) {
 	db := newInMemoryStore(b.TempDir(), 0, nil)
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := b.Context()
 	go db.Serve(ctx)
 	api := newAPISrv("127.0.0.1:0", tls.Certificate{}, db, nil, true, true, 1000, 1000)
 	srv := httptest.NewServer(http.HandlerFunc(api.handler))
diff --git a/cmd/strelaysrv/listener.go b/cmd/strelaysrv/listener.go
index 3c4a2e427..543cedaed 100644
--- a/cmd/strelaysrv/listener.go
+++ b/cmd/strelaysrv/listener.go
@@ -18,7 +18,7 @@ import (
 
 var (
 	outboxesMut    = sync.RWMutex{}
-	outboxes       = make(map[syncthingprotocol.DeviceID]chan interface{})
+	outboxes       = make(map[syncthingprotocol.DeviceID]chan any)
 	numConnections atomic.Int64
 )
 
@@ -97,9 +97,9 @@ func protocolConnectionHandler(tcpConn net.Conn, config *tls.Config, token strin
 
 	id := syncthingprotocol.NewDeviceID(certs[0].Raw)
 
-	messages := make(chan interface{})
+	messages := make(chan any)
 	errors := make(chan error, 1)
-	outbox := make(chan interface{})
+	outbox := make(chan any)
 
 	// Read messages from the connection and send them on the messages
 	// channel. When there is an error, send it on the error channel and
@@ -364,7 +364,7 @@ func sessionConnectionHandler(conn net.Conn) {
 	}
 }
 
-func messageReader(conn net.Conn, messages chan<- interface{}, errors chan<- error) {
+func messageReader(conn net.Conn, messages chan<- any, errors chan<- error) {
 	numConnections.Add(1)
 	defer numConnections.Add(-1)
 
diff --git a/cmd/strelaysrv/session.go b/cmd/strelaysrv/session.go
index 6e592d87b..d4f572849 100644
--- a/cmd/strelaysrv/session.go
+++ b/cmd/strelaysrv/session.go
@@ -330,10 +330,7 @@ func take(tokens int, ls ...*rate.Limiter) {
 
 	for tokens > 0 {
 		// chunk is how many tokens we can consume at a time
-		chunk := tokens
-		if chunk > minBurst {
-			chunk = minBurst
-		}
+		chunk := min(tokens, minBurst)
 
 		// maxDelay is the longest delay mandated by any of the limiters for
 		// the chosen chunk size.
diff --git a/cmd/strelaysrv/status.go b/cmd/strelaysrv/status.go
index 622ac4e4a..f0ee51926 100644
--- a/cmd/strelaysrv/status.go
+++ b/cmd/strelaysrv/status.go
@@ -38,7 +38,7 @@ func statusService(addr string) {
 
 func getStatus(w http.ResponseWriter, _ *http.Request) {
 	w.Header().Set("Access-Control-Allow-Origin", "*")
-	status := make(map[string]interface{})
+	status := make(map[string]any)
 
 	sessionMut.Lock()
 	// This can potentially be double the number of pending sessions, as each session has two keys, one for each side.
@@ -67,7 +67,7 @@ func getStatus(w http.ResponseWriter, _ *http.Request) {
 		rc.rate(30*60/10) * 8 / 1000,
 		rc.rate(60*60/10) * 8 / 1000,
 	}
-	status["options"] = map[string]interface{}{
+	status["options"] = map[string]any{
 		"network-timeout":  networkTimeout / time.Second,
 		"ping-interval":    pingInterval / time.Second,
 		"message-timeout":  messageTimeout / time.Second,
diff --git a/cmd/syncthing/cli/client.go b/cmd/syncthing/cli/client.go
index 0bfeb16b3..ace852b85 100644
--- a/cmd/syncthing/cli/client.go
+++ b/cmd/syncthing/cli/client.go
@@ -27,7 +27,7 @@ import (
 type APIClient interface {
 	Get(url string) (*http.Response, error)
 	Post(url, body string) (*http.Response, error)
-	PutJSON(url string, o interface{}) (*http.Response, error)
+	PutJSON(url string, o any) (*http.Response, error)
 }
 
 type apiClient struct {
@@ -134,7 +134,7 @@ func (c *apiClient) RequestString(url, method, data string) (*http.Response, err
 	return c.Request(url, method, bytes.NewBufferString(data))
 }
 
-func (c *apiClient) RequestJSON(url, method string, o interface{}) (*http.Response, error) {
+func (c *apiClient) RequestJSON(url, method string, o any) (*http.Response, error) {
 	data, err := json.Marshal(o)
 	if err != nil {
 		return nil, err
@@ -150,7 +150,7 @@ func (c *apiClient) Post(url, body string) (*http.Response, error) {
 	return c.RequestString(url, "POST", body)
 }
 
-func (c *apiClient) PutJSON(url string, o interface{}) (*http.Response, error) {
+func (c *apiClient) PutJSON(url string, o any) (*http.Response, error) {
 	return c.RequestJSON(url, "PUT", o)
 }
 
diff --git a/cmd/syncthing/cli/config.go b/cmd/syncthing/cli/config.go
index 1bb6dc000..ee59559ea 100644
--- a/cmd/syncthing/cli/config.go
+++ b/cmd/syncthing/cli/config.go
@@ -81,7 +81,7 @@ func (c *configCommand) Run(ctx Context, outerCtx *kong.Context) error {
 	app.Name = "syncthing cli config"
 	app.HelpName = "syncthing cli config"
 	app.Description = outerCtx.Selected().Help
-	app.Metadata = map[string]interface{}{
+	app.Metadata = map[string]any{
 		"clientFactory": ctx.clientFactory,
 	}
 	app.CustomAppHelpTemplate = customAppHelpTemplate
diff --git a/cmd/syncthing/cli/utils.go b/cmd/syncthing/cli/utils.go
index 35f64f970..6b71f5359 100644
--- a/cmd/syncthing/cli/utils.go
+++ b/cmd/syncthing/cli/utils.go
@@ -112,7 +112,7 @@ func getConfig(c APIClient) (config.Configuration, error) {
 	return cfg, nil
 }
 
-func prettyPrintJSON(data interface{}) error {
+func prettyPrintJSON(data any) error {
 	enc := json.NewEncoder(os.Stdout)
 	enc.SetIndent("", "  ")
 	return enc.Encode(data)
@@ -123,7 +123,7 @@ func prettyPrintResponse(response *http.Response) error {
 	if err != nil {
 		return err
 	}
-	var data interface{}
+	var data any
 	if err := json.Unmarshal(bytes, &data); err != nil {
 		return err
 	}
diff --git a/cmd/syncthing/crash_reporting.go b/cmd/syncthing/crash_reporting.go
index 6832192e8..d9788d83b 100644
--- a/cmd/syncthing/crash_reporting.go
+++ b/cmd/syncthing/crash_reporting.go
@@ -125,7 +125,7 @@ func uploadPanicLog(ctx context.Context, urlBase, file string) error {
 func filterLogLines(data []byte) []byte {
 	filtered := data[:0]
 	matched := false
-	for _, line := range bytes.Split(data, []byte("\n")) {
+	for line := range bytes.SplitSeq(data, []byte("\n")) {
 		switch {
 		case !matched && bytes.HasPrefix(line, []byte("Panic ")):
 			// This begins the panic trace, set the matched flag and append.
diff --git a/cmd/syncthing/hideconsole_others.go b/cmd/syncthing/hideconsole_others.go
index 0688dac1c..883b48985 100644
--- a/cmd/syncthing/hideconsole_others.go
+++ b/cmd/syncthing/hideconsole_others.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package main
 
diff --git a/cmd/syncthing/openurl_unix.go b/cmd/syncthing/openurl_unix.go
index 51e9b7350..32f14a697 100644
--- a/cmd/syncthing/openurl_unix.go
+++ b/cmd/syncthing/openurl_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package main
 
diff --git a/cmd/syncthing/openurl_windows.go b/cmd/syncthing/openurl_windows.go
index a89ea4b77..9554d10e9 100644
--- a/cmd/syncthing/openurl_windows.go
+++ b/cmd/syncthing/openurl_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package main
 
diff --git a/cmd/syncthing/perfstats_unix.go b/cmd/syncthing/perfstats_unix.go
index b02054b35..2e9160c9d 100644
--- a/cmd/syncthing/perfstats_unix.go
+++ b/cmd/syncthing/perfstats_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !solaris && !windows
-// +build !solaris,!windows
 
 package main
 
diff --git a/cmd/syncthing/perfstats_unsupported.go b/cmd/syncthing/perfstats_unsupported.go
index f60f8da12..f2efd8012 100644
--- a/cmd/syncthing/perfstats_unsupported.go
+++ b/cmd/syncthing/perfstats_unsupported.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build solaris || windows
-// +build solaris windows
 
 package main
 
diff --git a/cmd/syncthing/traceback.go b/cmd/syncthing/traceback.go
index 746bb2d87..194b89f7e 100644
--- a/cmd/syncthing/traceback.go
+++ b/cmd/syncthing/traceback.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build go1.7
-// +build go1.7
 
 package main
 
diff --git a/internal/db/sqlite/basedb.go b/internal/db/sqlite/basedb.go
index 71ca3105b..38b62f81b 100644
--- a/internal/db/sqlite/basedb.go
+++ b/internal/db/sqlite/basedb.go
@@ -313,7 +313,7 @@ nextScript:
 		// files on lines containing only a semicolon and execute them
 		// separately. We require it on a separate line because there are
 		// also statement-internal semicolons in the triggers.
-		for _, stmt := range strings.Split(string(bs), "\n;") {
+		for stmt := range strings.SplitSeq(string(bs), "\n;") {
 			if _, err := tx.Exec(s.expandTemplateVars(stmt)); err != nil {
 				if strings.Contains(stmt, "syncthing:ignore-failure") {
 					// We're ok with this failing. Just note it.
diff --git a/internal/db/sqlite/folderdb_update.go b/internal/db/sqlite/folderdb_update.go
index b6f9e53bc..ea95fc0e2 100644
--- a/internal/db/sqlite/folderdb_update.go
+++ b/internal/db/sqlite/folderdb_update.go
@@ -474,10 +474,7 @@ func (s *folderDB) recalcGlobalForFile(txp *txPreparedStmts, file string) error
 	// The global version is the first one in the list that is not invalid,
 	// or just the first one in the list if all are invalid.
 	var global fileRow
-	globIdx := slices.IndexFunc(es, func(e fileRow) bool { return !e.IsInvalid() })
-	if globIdx < 0 {
-		globIdx = 0
-	}
+	globIdx := max(slices.IndexFunc(es, func(e fileRow) bool { return !e.IsInvalid() }), 0)
 	global = es[globIdx]
 
 	// We "have" the file if the position in the list of versions is at the
diff --git a/internal/slogutil/leveler.go b/internal/slogutil/leveler.go
index 314480bb6..c83bd17d2 100644
--- a/internal/slogutil/leveler.go
+++ b/internal/slogutil/leveler.go
@@ -41,8 +41,8 @@ func SetDefaultLevel(level slog.Level) {
 }
 
 func SetLevelOverrides(sttrace string) {
-	pkgs := strings.Split(sttrace, ",")
-	for _, pkg := range pkgs {
+	pkgs := strings.SplitSeq(sttrace, ",")
+	for pkg := range pkgs {
 		pkg = strings.TrimSpace(pkg)
 		if pkg == "" {
 			continue
diff --git a/internal/slogutil/slogadapter.go b/internal/slogutil/slogadapter.go
index b30801be9..aa466e69f 100644
--- a/internal/slogutil/slogadapter.go
+++ b/internal/slogutil/slogadapter.go
@@ -45,11 +45,11 @@ type adapter struct {
 	l *slog.Logger
 }
 
-func (a adapter) Debugln(vals ...interface{}) {
+func (a adapter) Debugln(vals ...any) {
 	a.log(strings.TrimSpace(fmt.Sprintln(vals...)), slog.LevelDebug)
 }
 
-func (a adapter) Debugf(format string, vals ...interface{}) {
+func (a adapter) Debugf(format string, vals ...any) {
 	a.log(fmt.Sprintf(format, vals...), slog.LevelDebug)
 }
 
diff --git a/lib/api/api.go b/lib/api/api.go
index da34ec481..b82e12ca8 100644
--- a/lib/api/api.go
+++ b/lib/api/api.go
@@ -202,7 +202,7 @@ func (s *service) getListener(guiCfg config.GUIConfiguration) (net.Listener, err
 	return listener, nil
 }
 
-func sendJSON(w http.ResponseWriter, jsonObject interface{}) {
+func sendJSON(w http.ResponseWriter, jsonObject any) {
 	w.Header().Set("Content-Type", "application/json")
 	// Marshalling might fail, in which case we should return a 500 with the
 	// actual error.
@@ -696,7 +696,7 @@ func (*service) getSystemPaths(w http.ResponseWriter, _ *http.Request) {
 }
 
 func (s *service) getJSMetadata(w http.ResponseWriter, _ *http.Request) {
-	meta, _ := json.Marshal(map[string]interface{}{
+	meta, _ := json.Marshal(map[string]any{
 		"deviceID":      s.id.String(),
 		"deviceIDShort": s.id.Short().String(),
 		"authenticated": true,
@@ -706,7 +706,7 @@ func (s *service) getJSMetadata(w http.ResponseWriter, _ *http.Request) {
 }
 
 func (*service) getSystemVersion(w http.ResponseWriter, _ *http.Request) {
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"version":     build.Version,
 		"codename":    build.Codename,
 		"longVersion": build.LongVersion,
@@ -838,7 +838,7 @@ func (s *service) getDBNeed(w http.ResponseWriter, r *http.Request) {
 	}
 
 	// Convert the struct to a more loose structure, and inject the size.
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"progress": toJsonFileInfoSlice(progress),
 		"queued":   toJsonFileInfoSlice(queued),
 		"rest":     toJsonFileInfoSlice(rest),
@@ -866,7 +866,7 @@ func (s *service) getDBRemoteNeed(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"files":   toJsonFileInfoSlice(files),
 		"page":    page,
 		"perpage": perpage,
@@ -886,7 +886,7 @@ func (s *service) getDBLocalChanged(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"files":   toJsonFileInfoSlice(files),
 		"page":    page,
 		"perpage": perpage,
@@ -951,7 +951,7 @@ func (s *service) getDBFile(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"global":       jsonFileInfo(gf),
 		"local":        jsonFileInfo(lf),
 		"availability": av,
@@ -967,7 +967,7 @@ func (s *service) getDebugFile(w http.ResponseWriter, r *http.Request) {
 	gf, _, _ := s.model.CurrentGlobalFile(folder, file)
 	av, _ := s.model.Availability(folder, protocol.FileInfo{Name: file}, protocol.BlockInfo{})
 
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"global":       jsonFileInfo(gf),
 		"local":        jsonFileInfo(lf),
 		"availability": av,
@@ -1037,7 +1037,7 @@ func (s *service) getSystemStatus(w http.ResponseWriter, _ *http.Request) {
 	runtime.ReadMemStats(&m)
 
 	tilde, _ := fs.ExpandTilde("~")
-	res := make(map[string]interface{})
+	res := make(map[string]any)
 	res["myID"] = s.id.String()
 	res["goroutines"] = runtime.NumGoroutine()
 	res["alloc"] = m.Alloc
@@ -1302,7 +1302,7 @@ func (s *service) getDBIgnores(w http.ResponseWriter, r *http.Request) {
 	folder := qs.Get("folder")
 
 	lines, patterns, err := s.model.LoadIgnores(folder)
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"ignore":   lines,
 		"expanded": patterns,
 		"error":    errorString(err),
@@ -1411,7 +1411,7 @@ func (s *service) getSystemUpgrade(w http.ResponseWriter, _ *http.Request) {
 		httpError(w, err)
 		return
 	}
-	res := make(map[string]interface{})
+	res := make(map[string]any)
 	res["running"] = build.Version
 	res["latest"] = rel.Tag
 	res["newer"] = upgrade.CompareVersions(rel.Tag, build.Version) == upgrade.Newer
@@ -1439,7 +1439,7 @@ func (*service) getDeviceID(w http.ResponseWriter, r *http.Request) {
 func (*service) getLang(w http.ResponseWriter, r *http.Request) {
 	lang := r.Header.Get("Accept-Language")
 	weights := make(map[string]float64)
-	for _, l := range strings.Split(lang, ",") {
+	for l := range strings.SplitSeq(lang, ",") {
 		parts := strings.SplitN(l, ";", 2)
 		code := strings.ToLower(strings.TrimSpace(parts[0]))
 		weights[code] = 1.0
@@ -1638,7 +1638,7 @@ func (s *service) getFolderErrors(w http.ResponseWriter, r *http.Request) {
 		}
 	}
 
-	sendJSON(w, map[string]interface{}{
+	sendJSON(w, map[string]any{
 		"folder":  folder,
 		"errors":  errors,
 		"page":    page,
@@ -1770,8 +1770,8 @@ func (f jsonFileInfo) MarshalJSON() ([]byte, error) {
 	return json.Marshal(m)
 }
 
-func fileIntfJSONMap(f protocol.FileInfo) map[string]interface{} {
-	out := map[string]interface{}{
+func fileIntfJSONMap(f protocol.FileInfo) map[string]any {
+	out := map[string]any{
 		"name":               f.FileName(),
 		"type":               f.FileType().String(),
 		"size":               f.Size,
diff --git a/lib/api/api_auth.go b/lib/api/api_auth.go
index ad2225994..ab4d72e16 100644
--- a/lib/api/api_auth.go
+++ b/lib/api/api_auth.go
@@ -311,10 +311,7 @@ func authLDAP(username string, password string, cfg config.LDAPConfiguration) bo
 
 func formatOptionalPercentS(template string, username string) string {
 	var replacements []any
-	nReps := strings.Count(template, "%s") - strings.Count(template, "%%s")
-	if nReps < 0 {
-		nReps = 0
-	}
+	nReps := max(strings.Count(template, "%s")-strings.Count(template, "%%s"), 0)
 	for range nReps {
 		replacements = append(replacements, username)
 	}
diff --git a/lib/api/api_test.go b/lib/api/api_test.go
index bc6a27098..a1e298f0a 100644
--- a/lib/api/api_test.go
+++ b/lib/api/api_test.go
@@ -433,7 +433,6 @@ func TestAPIServiceRequests(t *testing.T) {
 	}
 
 	for _, tc := range cases {
-		tc := tc
 		t.Run(tc.URL, func(t *testing.T) {
 			t.Parallel()
 			testHTTPRequest(t, baseURL, tc, testAPIKey)
@@ -1723,7 +1722,7 @@ func TestConfigChanges(t *testing.T) {
 		return resp
 	}
 
-	mod := func(method, path string, data interface{}) {
+	mod := func(method, path string, data any) {
 		t.Helper()
 		bs, err := json.Marshal(data)
 		if err != nil {
diff --git a/lib/api/auto/noassets.go b/lib/api/auto/noassets.go
index 977d3d4a4..e75065a2e 100644
--- a/lib/api/auto/noassets.go
+++ b/lib/api/auto/noassets.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build noassets
-// +build noassets
 
 package auto
 
diff --git a/lib/api/confighandler.go b/lib/api/confighandler.go
index ec622504f..2f6b1f31e 100644
--- a/lib/api/confighandler.go
+++ b/lib/api/confighandler.go
@@ -441,7 +441,7 @@ func (c *configMuxBuilder) adjustLDAP(w http.ResponseWriter, r *http.Request, ld
 }
 
 // Unmarshals the content of the given body and stores it in to (i.e. to must be a pointer).
-func unmarshalTo(body io.ReadCloser, to interface{}) error {
+func unmarshalTo(body io.ReadCloser, to any) error {
 	bs, err := io.ReadAll(body)
 	body.Close()
 	if err != nil {
diff --git a/lib/build/tags_race.go b/lib/build/tags_race.go
index cbcc5b9c7..26e71574d 100644
--- a/lib/build/tags_race.go
+++ b/lib/build/tags_race.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build race
-// +build race
 
 package build
 
diff --git a/lib/config/config.go b/lib/config/config.go
index 4407cf35b..76d66aad7 100644
--- a/lib/config/config.go
+++ b/lib/config/config.go
@@ -664,7 +664,7 @@ func (defaults *Defaults) prepare(myID protocol.DeviceID, existingDevices map[pr
 	defaults.Device.prepare(nil)
 }
 
-func ensureZeroForNodefault(empty interface{}, target interface{}) {
+func ensureZeroForNodefault(empty any, target any) {
 	copyMatchingTag(empty, target, "nodefault", func(v string) bool {
 		if len(v) > 0 && v != "true" {
 			panic(fmt.Sprintf(`unexpected tag value: %s. expected untagged or "true"`, v))
@@ -674,7 +674,7 @@ func ensureZeroForNodefault(empty interface{}, target interface{}) {
 }
 
 // copyMatchingTag copies fields tagged tag:"value" from "from" struct onto "to" struct.
-func copyMatchingTag(from interface{}, to interface{}, tag string, shouldCopy func(value string) bool) {
+func copyMatchingTag(from any, to any, tag string, shouldCopy func(value string) bool) {
 	fromStruct := reflect.ValueOf(from).Elem()
 	fromType := fromStruct.Type()
 
diff --git a/lib/config/config_test.go b/lib/config/config_test.go
index a82d8e90d..7d4e4024a 100644
--- a/lib/config/config_test.go
+++ b/lib/config/config_test.go
@@ -1158,8 +1158,8 @@ func TestInvalidDeviceIDRejected(t *testing.T) {
 
 		// Change the device ID of the first device to "invalid". Fast and loose
 		// with the type assertions as we know what the JSON decoder returns.
-		devs := cfg["devices"].([]interface{})
-		dev0 := devs[0].(map[string]interface{})
+		devs := cfg["devices"].([]any)
+		dev0 := devs[0].(map[string]any)
 		dev0["deviceID"] = tc.id
 		devs[0] = dev0
 
@@ -1197,8 +1197,8 @@ func TestInvalidFolderIDRejected(t *testing.T) {
 		// Change the folder ID of the first folder to the empty string.
 		// Fast and loose with the type assertions as we know what the JSON
 		// decoder returns.
-		devs := cfg["folders"].([]interface{})
-		dev0 := devs[0].(map[string]interface{})
+		devs := cfg["folders"].([]any)
+		dev0 := devs[0].(map[string]any)
 		dev0["id"] = tc.id
 		devs[0] = dev0
 
@@ -1324,7 +1324,7 @@ func adjustFolderConfiguration(cfg *FolderConfiguration, id, label string, fsTyp
 // defaultConfigAsMap returns a valid default config as a JSON-decoded
 // map[string]interface{}. This is useful to override random elements and
 // re-encode into JSON.
-func defaultConfigAsMap() map[string]interface{} {
+func defaultConfigAsMap() map[string]any {
 	cfg := New(device1)
 	dev := cfg.Defaults.Device.Copy()
 	adjustDeviceConfiguration(&dev, device2, "name")
@@ -1337,7 +1337,7 @@ func defaultConfigAsMap() map[string]interface{} {
 		// can't happen
 		panic(err)
 	}
-	var tmp map[string]interface{}
+	var tmp map[string]any
 	if err := json.Unmarshal(bs, &tmp); err != nil {
 		// can't happen
 		panic(err)
diff --git a/lib/config/versioningconfiguration.go b/lib/config/versioningconfiguration.go
index 66327aa8e..2e4291e05 100644
--- a/lib/config/versioningconfiguration.go
+++ b/lib/config/versioningconfiguration.go
@@ -9,6 +9,7 @@ package config
 import (
 	"encoding/json"
 	"encoding/xml"
+	"maps"
 	"slices"
 	"strings"
 
@@ -45,9 +46,7 @@ type internalParam struct {
 func (c VersioningConfiguration) Copy() VersioningConfiguration {
 	cp := c
 	cp.Params = make(map[string]string, len(c.Params))
-	for k, v := range c.Params {
-		cp.Params[k] = v
-	}
+	maps.Copy(cp.Params, c.Params)
 	return cp
 }
 
diff --git a/lib/connections/connections_test.go b/lib/connections/connections_test.go
index afb196b8b..7488157ce 100644
--- a/lib/connections/connections_test.go
+++ b/lib/connections/connections_test.go
@@ -401,7 +401,7 @@ func TestConnectionEstablishment(t *testing.T) {
 	}
 }
 
-func withConnectionPair(b interface{ Fatal(...interface{}) }, connUri string, h func(client, server internalConn)) {
+func withConnectionPair(b interface{ Fatal(...any) }, connUri string, h func(client, server internalConn)) {
 	// Root of the service tree.
 	supervisor := suture.New("main", suture.Spec{
 		PassThroughPanics: true,
@@ -494,7 +494,7 @@ func withConnectionPair(b interface{ Fatal(...interface{}) }, connUri string, h
 	_ = serverConn.Close()
 }
 
-func mustGetCert(b interface{ Fatal(...interface{}) }) tls.Certificate {
+func mustGetCert(b interface{ Fatal(...any) }) tls.Certificate {
 	cert, err := tlsutil.NewCertificateInMemory("bench", 10)
 	if err != nil {
 		b.Fatal(err)
diff --git a/lib/connections/dialqueue_test.go b/lib/connections/dialqueue_test.go
index bdf33bc0a..5bdb162d8 100644
--- a/lib/connections/dialqueue_test.go
+++ b/lib/connections/dialqueue_test.go
@@ -54,7 +54,7 @@ func TestDialQueueSort(t *testing.T) {
 
 		var seen1, seen2 int
 
-		for i := 0; i < 100; i++ {
+		for range 100 {
 			queue.Sort()
 			res := shortDevices(queue)
 			if reflect.DeepEqual(res, expected1) {
@@ -90,7 +90,7 @@ func TestDialQueueSort(t *testing.T) {
 
 		var seen1, seen2 int
 
-		for i := 0; i < 100; i++ {
+		for range 100 {
 			queue.Sort()
 			res := shortDevices(queue)
 			if reflect.DeepEqual(res, expected1) {
diff --git a/lib/connections/limiter.go b/lib/connections/limiter.go
index d5e0bd56b..8e713c1e0 100644
--- a/lib/connections/limiter.go
+++ b/lib/connections/limiter.go
@@ -256,18 +256,14 @@ func (w *limitedWriter) Write(buf []byte) (int, error) {
 	// try to be a bit adaptable. We range from the minimum write size of 1
 	// KiB up to the limiter burst size, aiming for about a write every
 	// 10ms.
-	singleWriteSize := int(w.waiter.Limit() / 100)          // 10ms worth of data
-	singleWriteSize = ((singleWriteSize / 1024) + 1) * 1024 // round up to the next kibibyte
-	if singleWriteSize > limiterBurstSize {
-		singleWriteSize = limiterBurstSize
-	}
+	singleWriteSize := int(w.waiter.Limit() / 100) // 10ms worth of data
+	singleWriteSize = min(
+		// round up to the next kibibyte
+		((singleWriteSize/1024)+1)*1024, limiterBurstSize)
 
 	written := 0
 	for written < len(buf) {
-		toWrite := singleWriteSize
-		if toWrite > len(buf)-written {
-			toWrite = len(buf) - written
-		}
+		toWrite := min(singleWriteSize, len(buf)-written)
 		w.take(toWrite)
 		n, err := w.writer.Write(buf[written : written+toWrite])
 		written += n
diff --git a/lib/connections/quic_dial.go b/lib/connections/quic_dial.go
index 1deda0ea3..fea0bd286 100644
--- a/lib/connections/quic_dial.go
+++ b/lib/connections/quic_dial.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build go1.15 && !noquic
-// +build go1.15,!noquic
 
 package connections
 
diff --git a/lib/connections/quic_listen.go b/lib/connections/quic_listen.go
index ccb20456a..2615d8d30 100644
--- a/lib/connections/quic_listen.go
+++ b/lib/connections/quic_listen.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build !noquic
-// +build !noquic
 
 package connections
 
diff --git a/lib/connections/quic_misc.go b/lib/connections/quic_misc.go
index 16d21cae2..62fc60dff 100644
--- a/lib/connections/quic_misc.go
+++ b/lib/connections/quic_misc.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build !noquic
-// +build !noquic
 
 package connections
 
diff --git a/lib/connections/quic_unsupported.go b/lib/connections/quic_unsupported.go
index 274b57587..a2bf3dfd0 100644
--- a/lib/connections/quic_unsupported.go
+++ b/lib/connections/quic_unsupported.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build noquic
-// +build noquic
 
 package connections
 
diff --git a/lib/connections/registry/registry.go b/lib/connections/registry/registry.go
index cf99720a8..70f2409dd 100644
--- a/lib/connections/registry/registry.go
+++ b/lib/connections/registry/registry.go
@@ -18,23 +18,23 @@ import (
 
 type Registry struct {
 	mut       sync.Mutex
-	available map[string][]interface{}
+	available map[string][]any
 }
 
 func New() *Registry {
 	return &Registry{
-		available: make(map[string][]interface{}),
+		available: make(map[string][]any),
 	}
 }
 
-func (r *Registry) Register(scheme string, item interface{}) {
+func (r *Registry) Register(scheme string, item any) {
 	r.mut.Lock()
 	defer r.mut.Unlock()
 
 	r.available[scheme] = append(r.available[scheme], item)
 }
 
-func (r *Registry) Unregister(scheme string, item interface{}) {
+func (r *Registry) Unregister(scheme string, item any) {
 	r.mut.Lock()
 	defer r.mut.Unlock()
 
@@ -49,12 +49,12 @@ func (r *Registry) Unregister(scheme string, item interface{}) {
 
 // Get returns an item for a schema compatible with the given scheme.
 // If any item satisfies preferred, that has precedence over other items.
-func (r *Registry) Get(scheme string, preferred func(interface{}) bool) interface{} {
+func (r *Registry) Get(scheme string, preferred func(any) bool) any {
 	r.mut.Lock()
 	defer r.mut.Unlock()
 
 	var (
-		best       interface{}
+		best       any
 		bestPref   bool
 		bestScheme string
 	)
diff --git a/lib/connections/registry/registry_test.go b/lib/connections/registry/registry_test.go
index bf7a2e24a..26337e018 100644
--- a/lib/connections/registry/registry_test.go
+++ b/lib/connections/registry/registry_test.go
@@ -14,8 +14,8 @@ import (
 func TestRegistry(t *testing.T) {
 	r := New()
 
-	want := func(i int) func(interface{}) bool {
-		return func(x interface{}) bool { return x.(int) == i }
+	want := func(i int) func(any) bool {
+		return func(x any) bool { return x.(int) == i }
 	}
 
 	if res := r.Get("int", want(1)); res != nil {
@@ -73,7 +73,7 @@ func TestShortSchemeFirst(t *testing.T) {
 	r.Register("foobar", 1)
 
 	// If we don't care about the value, we should get the one with "foo".
-	res := r.Get("foo", func(interface{}) bool { return false })
+	res := r.Get("foo", func(any) bool { return false })
 	if res != 0 {
 		t.Error("unexpected", res)
 	}
@@ -89,7 +89,7 @@ func BenchmarkGet(b *testing.B) {
 	b.ResetTimer()
 
 	for i := 0; i < b.N; i++ {
-		r.Get("tcp", func(x interface{}) bool {
+		r.Get("tcp", func(x any) bool {
 			return x.(*net.TCPAddr).IP.IsUnspecified()
 		})
 	}
diff --git a/lib/connections/service.go b/lib/connections/service.go
index 0cf96956f..cd0dd701c 100644
--- a/lib/connections/service.go
+++ b/lib/connections/service.go
@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"io"
 	"log/slog"
+	"maps"
 	"math"
 	"net"
 	"net/url"
@@ -817,7 +818,7 @@ func (s *service) createListener(factory listenerFactory, uri *url.URL) bool {
 }
 
 func (s *service) logListenAddressesChangedEvent(l ListenerAddresses) {
-	s.evLogger.Log(events.ListenAddressesChanged, map[string]interface{}{
+	s.evLogger.Log(events.ListenAddressesChanged, map[string]any{
 		"address": l.URI,
 		"lan":     l.LANAddresses,
 		"wan":     l.WANAddresses,
@@ -995,9 +996,7 @@ func newConnectionStatusHandler() connectionStatusHandler {
 func (s *connectionStatusHandler) ConnectionStatus() map[string]ConnectionStatusEntry {
 	result := make(map[string]ConnectionStatusEntry)
 	s.connectionStatusMut.RLock()
-	for k, v := range s.connectionStatus {
-		result[k] = v
-	}
+	maps.Copy(result, s.connectionStatus)
 	s.connectionStatusMut.RUnlock()
 	return result
 }
diff --git a/lib/dialer/control_unix.go b/lib/dialer/control_unix.go
index dc50a52af..822a8ed55 100644
--- a/lib/dialer/control_unix.go
+++ b/lib/dialer/control_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !solaris && !windows
-// +build !solaris,!windows
 
 package dialer
 
diff --git a/lib/dialer/control_unsupported.go b/lib/dialer/control_unsupported.go
index 835525d4f..2b94e70a8 100644
--- a/lib/dialer/control_unsupported.go
+++ b/lib/dialer/control_unsupported.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build solaris
-// +build solaris
 
 package dialer
 
diff --git a/lib/dialer/control_windows.go b/lib/dialer/control_windows.go
index 289921f7d..cd1a8b636 100644
--- a/lib/dialer/control_windows.go
+++ b/lib/dialer/control_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package dialer
 
diff --git a/lib/dialer/public.go b/lib/dialer/public.go
index 9310cca77..1844af9e8 100644
--- a/lib/dialer/public.go
+++ b/lib/dialer/public.go
@@ -111,7 +111,7 @@ func DialContextReusePortFunc(registry *registry.Registry) func(ctx context.Cont
 			return DialContext(ctx, network, addr)
 		}
 
-		localAddrInterface := registry.Get(network, func(addr interface{}) bool {
+		localAddrInterface := registry.Get(network, func(addr any) bool {
 			return addr.(*net.TCPAddr).IP.IsUnspecified()
 		})
 		if localAddrInterface == nil {
diff --git a/lib/discover/cache.go b/lib/discover/cache.go
index 87ba28616..ea00966e3 100644
--- a/lib/discover/cache.go
+++ b/lib/discover/cache.go
@@ -7,6 +7,7 @@
 package discover
 
 import (
+	"maps"
 	"sync"
 	"time"
 
@@ -60,9 +61,7 @@ func (c *cache) Get(id protocol.DeviceID) (CacheEntry, bool) {
 func (c *cache) Cache() map[protocol.DeviceID]CacheEntry {
 	c.mut.Lock()
 	m := make(map[protocol.DeviceID]CacheEntry, len(c.entries))
-	for k, v := range c.entries {
-		m[k] = v
-	}
+	maps.Copy(m, c.entries)
 	c.mut.Unlock()
 	return m
 }
diff --git a/lib/discover/local.go b/lib/discover/local.go
index 248b603a9..585bcae0b 100644
--- a/lib/discover/local.go
+++ b/lib/discover/local.go
@@ -294,7 +294,7 @@ func (c *localClient) registerDevice(src net.Addr, device *discoproto.Announce)
 	})
 
 	if isNewDevice {
-		c.evLogger.Log(events.DeviceDiscovered, map[string]interface{}{
+		c.evLogger.Log(events.DeviceDiscovered, map[string]any{
 			"device": id.String(),
 			"addrs":  validAddresses,
 		})
diff --git a/lib/events/events.go b/lib/events/events.go
index 1504db40e..199d72d2d 100644
--- a/lib/events/events.go
+++ b/lib/events/events.go
@@ -235,7 +235,7 @@ const BufferSize = 64
 
 type Logger interface {
 	suture.Service
-	Log(t EventType, data interface{})
+	Log(t EventType, data any)
 	Subscribe(mask EventType) Subscription
 }
 
@@ -253,10 +253,10 @@ type Event struct {
 	// Per-subscription sequential event ID. Named "id" for backwards compatibility with the REST API
 	SubscriptionID int `json:"id"`
 	// Global ID of the event across all subscriptions
-	GlobalID int         `json:"globalID"`
-	Time     time.Time   `json:"time"`
-	Type     EventType   `json:"type"`
-	Data     interface{} `json:"data"`
+	GlobalID int       `json:"globalID"`
+	Time     time.Time `json:"time"`
+	Type     EventType `json:"type"`
+	Data     any       `json:"data"`
 }
 
 type Subscription interface {
@@ -325,7 +325,7 @@ loop:
 	return nil
 }
 
-func (l *logger) Log(t EventType, data interface{}) {
+func (l *logger) Log(t EventType, data any) {
 	l.events <- Event{
 		Time: time.Now(), // intentionally high precision
 		Type: t,
@@ -559,7 +559,7 @@ var NoopLogger Logger = &noopLogger{}
 
 func (*noopLogger) Serve(_ context.Context) error { return nil }
 
-func (*noopLogger) Log(_ EventType, _ interface{}) {}
+func (*noopLogger) Log(_ EventType, _ any) {}
 
 func (*noopLogger) Subscribe(_ EventType) Subscription {
 	return &noopSubscription{}
diff --git a/lib/events/events_test.go b/lib/events/events_test.go
index fbaad59c4..f01853c7a 100644
--- a/lib/events/events_test.go
+++ b/lib/events/events_test.go
@@ -127,7 +127,7 @@ func TestBufferOverflow(t *testing.T) {
 
 	t0 := time.Now()
 	const nEvents = BufferSize * 2
-	for i := 0; i < nEvents; i++ {
+	for range nEvents {
 		l.Log(DeviceConnected, "foo")
 	}
 	if d := time.Since(t0); d > 15*time.Second {
@@ -237,7 +237,7 @@ func TestBufferedSub(t *testing.T) {
 	bs := NewBufferedSubscription(s, 10*BufferSize)
 
 	go func() {
-		for i := 0; i < 10*BufferSize; i++ {
+		for i := range 10 * BufferSize {
 			l.Log(DeviceConnected, fmt.Sprintf("event-%d", i))
 			if i%30 == 0 {
 				// Give the buffer routine time to pick up the events
@@ -378,7 +378,7 @@ func TestUnsubscribeContention(t *testing.T) {
 
 	stopListeners := make(chan struct{})
 	var listenerWg sync.WaitGroup
-	for i := 0; i < listeners; i++ {
+	for range listeners {
 		listenerWg.Go(func() {
 			s := l.Subscribe(AllEvents)
 			defer s.Unsubscribe()
@@ -400,7 +400,7 @@ func TestUnsubscribeContention(t *testing.T) {
 	stopSenders := make(chan struct{})
 	defer close(stopSenders)
 	var senderWg sync.WaitGroup
-	for i := 0; i < senders; i++ {
+	for range senders {
 		senderWg.Go(func() {
 			t := time.NewTicker(time.Millisecond)
 
diff --git a/lib/fs/basicfs_copy_range_copyfilerange.go b/lib/fs/basicfs_copy_range_copyfilerange.go
index e7a814863..a915e82c9 100644
--- a/lib/fs/basicfs_copy_range_copyfilerange.go
+++ b/lib/fs/basicfs_copy_range_copyfilerange.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build linux
-// +build linux
 
 package fs
 
diff --git a/lib/fs/basicfs_copy_range_duplicateextents.go b/lib/fs/basicfs_copy_range_duplicateextents.go
index cdc587e57..91ac170b2 100644
--- a/lib/fs/basicfs_copy_range_duplicateextents.go
+++ b/lib/fs/basicfs_copy_range_duplicateextents.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package fs
 
diff --git a/lib/fs/basicfs_copy_range_ioctl.go b/lib/fs/basicfs_copy_range_ioctl.go
index 3c7cdbaad..362f22100 100644
--- a/lib/fs/basicfs_copy_range_ioctl.go
+++ b/lib/fs/basicfs_copy_range_ioctl.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build linux
-// +build linux
 
 package fs
 
diff --git a/lib/fs/basicfs_copy_range_sendfile.go b/lib/fs/basicfs_copy_range_sendfile.go
index 5b68d66fd..52e9b4930 100644
--- a/lib/fs/basicfs_copy_range_sendfile.go
+++ b/lib/fs/basicfs_copy_range_sendfile.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build linux || solaris
-// +build linux solaris
 
 package fs
 
diff --git a/lib/fs/basicfs_fileinfo_unix.go b/lib/fs/basicfs_fileinfo_unix.go
index cac1f451e..7a99bd919 100644
--- a/lib/fs/basicfs_fileinfo_unix.go
+++ b/lib/fs/basicfs_fileinfo_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package fs
 
diff --git a/lib/fs/basicfs_lstat_broken.go b/lib/fs/basicfs_lstat_broken.go
index d2678a4f1..2f615d5c8 100644
--- a/lib/fs/basicfs_lstat_broken.go
+++ b/lib/fs/basicfs_lstat_broken.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build linux || android
-// +build linux android
 
 package fs
 
diff --git a/lib/fs/basicfs_lstat_regular.go b/lib/fs/basicfs_lstat_regular.go
index e3a6176d3..f9bd74560 100644
--- a/lib/fs/basicfs_lstat_regular.go
+++ b/lib/fs/basicfs_lstat_regular.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !linux && !android && !windows
-// +build !linux,!android,!windows
 
 package fs
 
diff --git a/lib/fs/basicfs_lstat_windows.go b/lib/fs/basicfs_lstat_windows.go
index 93cf7be63..35f09526d 100644
--- a/lib/fs/basicfs_lstat_windows.go
+++ b/lib/fs/basicfs_lstat_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package fs
 
diff --git a/lib/fs/basicfs_platformdata_unix.go b/lib/fs/basicfs_platformdata_unix.go
index f87296f66..425a2a082 100644
--- a/lib/fs/basicfs_platformdata_unix.go
+++ b/lib/fs/basicfs_platformdata_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package fs
 
diff --git a/lib/fs/basicfs_test.go b/lib/fs/basicfs_test.go
index 4d194f3ed..f5a975ffb 100644
--- a/lib/fs/basicfs_test.go
+++ b/lib/fs/basicfs_test.go
@@ -580,7 +580,7 @@ func TestXattr(t *testing.T) {
 
 	// Create a set of random attributes that we will set and read back
 	var attrs []protocol.Xattr
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		key := fmt.Sprintf("user.test-%d", i)
 		value := make([]byte, xattrSize())
 		rand.Read(value)
diff --git a/lib/fs/basicfs_unix.go b/lib/fs/basicfs_unix.go
index 97e24bd4d..a26da05fc 100644
--- a/lib/fs/basicfs_unix.go
+++ b/lib/fs/basicfs_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_errors_linux.go b/lib/fs/basicfs_watch_errors_linux.go
index dfd472258..afcde6636 100644
--- a/lib/fs/basicfs_watch_errors_linux.go
+++ b/lib/fs/basicfs_watch_errors_linux.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build linux
-// +build linux
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_errors_others.go b/lib/fs/basicfs_watch_errors_others.go
index 3944061b5..99fec4358 100644
--- a/lib/fs/basicfs_watch_errors_others.go
+++ b/lib/fs/basicfs_watch_errors_others.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build !linux
-// +build !linux
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_eventtypes_darwin.go b/lib/fs/basicfs_watch_eventtypes_darwin.go
index e8fa49a08..caf6bafb2 100644
--- a/lib/fs/basicfs_watch_eventtypes_darwin.go
+++ b/lib/fs/basicfs_watch_eventtypes_darwin.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build darwin && !kqueue && cgo && !ios
-// +build darwin,!kqueue,cgo,!ios
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_eventtypes_fen.go b/lib/fs/basicfs_watch_eventtypes_fen.go
index eae07e2d0..7dfa939c4 100644
--- a/lib/fs/basicfs_watch_eventtypes_fen.go
+++ b/lib/fs/basicfs_watch_eventtypes_fen.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build solaris && cgo
-// +build solaris,cgo
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_eventtypes_inotify.go b/lib/fs/basicfs_watch_eventtypes_inotify.go
index bc06bf564..727c0b35b 100644
--- a/lib/fs/basicfs_watch_eventtypes_inotify.go
+++ b/lib/fs/basicfs_watch_eventtypes_inotify.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build linux
-// +build linux
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_eventtypes_kqueue.go b/lib/fs/basicfs_watch_eventtypes_kqueue.go
index 2232af79d..a852137e8 100644
--- a/lib/fs/basicfs_watch_eventtypes_kqueue.go
+++ b/lib/fs/basicfs_watch_eventtypes_kqueue.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build dragonfly || freebsd || netbsd || openbsd || ios || kqueue
-// +build dragonfly freebsd netbsd openbsd ios kqueue
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_eventtypes_other.go b/lib/fs/basicfs_watch_eventtypes_other.go
index cf08856f7..fdf637b51 100644
--- a/lib/fs/basicfs_watch_eventtypes_other.go
+++ b/lib/fs/basicfs_watch_eventtypes_other.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build !linux && !windows && !dragonfly && !freebsd && !netbsd && !openbsd && !solaris && !darwin && !cgo && !ios
-// +build !linux,!windows,!dragonfly,!freebsd,!netbsd,!openbsd,!solaris,!darwin,!cgo,!ios
 
 // Catch all platforms that are not specifically handled to use the generic
 // event types.
diff --git a/lib/fs/basicfs_watch_eventtypes_readdcw.go b/lib/fs/basicfs_watch_eventtypes_readdcw.go
index 5d4aa68f2..247da5f5f 100644
--- a/lib/fs/basicfs_watch_eventtypes_readdcw.go
+++ b/lib/fs/basicfs_watch_eventtypes_readdcw.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_notkqueue.go b/lib/fs/basicfs_watch_notkqueue.go
index de90c80cb..ec85df95b 100644
--- a/lib/fs/basicfs_watch_notkqueue.go
+++ b/lib/fs/basicfs_watch_notkqueue.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build !dragonfly && !freebsd && !netbsd && !openbsd && !kqueue && !ios
-// +build !dragonfly,!freebsd,!netbsd,!openbsd,!kqueue,!ios
 
 package fs
 
diff --git a/lib/fs/basicfs_watch_test.go b/lib/fs/basicfs_watch_test.go
index 290434c41..65b586e19 100644
--- a/lib/fs/basicfs_watch_test.go
+++ b/lib/fs/basicfs_watch_test.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build (!solaris && !darwin) || (solaris && cgo) || (darwin && cgo)
-// +build !solaris,!darwin solaris,cgo darwin,cgo
 
 package fs
 
@@ -364,8 +363,7 @@ func TestWatchSymlinkedRoot(t *testing.T) {
 
 	linkedFs := NewFilesystem(FilesystemTypeBasic, filepath.Join(testFs.URI(), link))
 
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 	if _, _, err := linkedFs.Watch(".", fakeMatcher{}, ctx, false); err != nil {
 		panic(err)
 	}
@@ -635,6 +633,6 @@ func (fakeEventInfo) Event() notify.Event {
 	return notify.Write
 }
 
-func (fakeEventInfo) Sys() interface{} {
+func (fakeEventInfo) Sys() any {
 	return nil
 }
diff --git a/lib/fs/basicfs_watch_unsupported.go b/lib/fs/basicfs_watch_unsupported.go
index 59ab2ea5c..6ea5cd2ab 100644
--- a/lib/fs/basicfs_watch_unsupported.go
+++ b/lib/fs/basicfs_watch_unsupported.go
@@ -5,7 +5,6 @@
 // You can obtain one at http://mozilla.org/MPL/2.0/.
 
 //go:build (solaris && !cgo) || (darwin && !cgo) || (darwin && kqueue)
-// +build solaris,!cgo darwin,!cgo darwin,kqueue
 
 package fs
 
diff --git a/lib/fs/basicfs_windows_test.go b/lib/fs/basicfs_windows_test.go
index 22519335f..42e79ad1e 100644
--- a/lib/fs/basicfs_windows_test.go
+++ b/lib/fs/basicfs_windows_test.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package fs
 
diff --git a/lib/fs/basicfs_xattr_bsdish.go b/lib/fs/basicfs_xattr_bsdish.go
index c22d2b73c..8faa22ac3 100644
--- a/lib/fs/basicfs_xattr_bsdish.go
+++ b/lib/fs/basicfs_xattr_bsdish.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build freebsd || netbsd
-// +build freebsd netbsd
 
 package fs
 
diff --git a/lib/fs/basicfs_xattr_linuxish.go b/lib/fs/basicfs_xattr_linuxish.go
index 4df9921d8..6036fb4c7 100644
--- a/lib/fs/basicfs_xattr_linuxish.go
+++ b/lib/fs/basicfs_xattr_linuxish.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build linux || darwin
-// +build linux darwin
 
 package fs
 
diff --git a/lib/fs/basicfs_xattr_unix.go b/lib/fs/basicfs_xattr_unix.go
index f32929708..ceec79937 100644
--- a/lib/fs/basicfs_xattr_unix.go
+++ b/lib/fs/basicfs_xattr_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows && !dragonfly && !illumos && !solaris && !openbsd
-// +build !windows,!dragonfly,!illumos,!solaris,!openbsd
 
 package fs
 
diff --git a/lib/fs/basicfs_xattr_unsupported.go b/lib/fs/basicfs_xattr_unsupported.go
index 6ade64f14..95031ffb3 100644
--- a/lib/fs/basicfs_xattr_unsupported.go
+++ b/lib/fs/basicfs_xattr_unsupported.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows || dragonfly || illumos || solaris || openbsd
-// +build windows dragonfly illumos solaris openbsd
 
 package fs
 
diff --git a/lib/fs/fakefs.go b/lib/fs/fakefs.go
index ff69dfd32..bbb357841 100644
--- a/lib/fs/fakefs.go
+++ b/lib/fs/fakefs.go
@@ -1017,6 +1017,6 @@ func (f *fakeFileInfo) Group() int {
 	return f.gid
 }
 
-func (*fakeFileInfo) Sys() interface{} {
+func (*fakeFileInfo) Sys() any {
 	return nil
 }
diff --git a/lib/fs/filesystem.go b/lib/fs/filesystem.go
index b001dcefc..863a91333 100644
--- a/lib/fs/filesystem.go
+++ b/lib/fs/filesystem.go
@@ -95,7 +95,7 @@ type FileInfo interface {
 	Size() int64
 	ModTime() time.Time
 	IsDir() bool
-	Sys() interface{}
+	Sys() any
 	// Extensions
 	IsRegular() bool
 	IsSymlink() bool
diff --git a/lib/fs/util.go b/lib/fs/util.go
index e4de09e45..33dc4f9a0 100644
--- a/lib/fs/util.go
+++ b/lib/fs/util.go
@@ -192,10 +192,7 @@ func CommonPrefix(first, second string) string {
 
 	isAbs := filepath.IsAbs(first) && filepath.IsAbs(second)
 
-	count := len(firstParts)
-	if len(secondParts) < len(firstParts) {
-		count = len(secondParts)
-	}
+	count := min(len(secondParts), len(firstParts))
 
 	common := make([]string, 0, count)
 	for i := range count {
diff --git a/lib/fs/util_test.go b/lib/fs/util_test.go
index 0be64b0f4..d08f59c7c 100644
--- a/lib/fs/util_test.go
+++ b/lib/fs/util_test.go
@@ -106,7 +106,7 @@ func TestSanitizePath(t *testing.T) {
 func TestSanitizePathFuzz(t *testing.T) {
 	buf := make([]byte, 128)
 
-	for i := 0; i < 100; i++ {
+	for range 100 {
 		rand.Read(buf)
 		path := SanitizePath(string(buf))
 		if !utf8.ValidString(path) {
diff --git a/lib/httpcache/httpcache.go b/lib/httpcache/httpcache.go
index 41002c52c..f9395ef45 100644
--- a/lib/httpcache/httpcache.go
+++ b/lib/httpcache/httpcache.go
@@ -11,6 +11,7 @@ import (
 	"compress/gzip"
 	"context"
 	"fmt"
+	"maps"
 	"net/http"
 	"strconv"
 	"strings"
@@ -43,9 +44,7 @@ type recordedResponse struct {
 }
 
 func (resp *recordedResponse) ServeHTTP(w http.ResponseWriter, r *http.Request) {
-	for k, v := range resp.header {
-		w.Header()[k] = v
-	}
+	maps.Copy(w.Header(), resp.header)
 
 	w.Header().Set("Cache-Control", fmt.Sprintf("public, max-age=%d", int(resp.keep.Seconds())))
 
diff --git a/lib/ignore/ignore_test.go b/lib/ignore/ignore_test.go
index de5fe913b..b8695e4eb 100644
--- a/lib/ignore/ignore_test.go
+++ b/lib/ignore/ignore_test.go
@@ -925,7 +925,7 @@ func TestIssue4901(t *testing.T) {
 	}
 
 	// Cache does not suddenly make the load succeed.
-	for i := 0; i < 2; i++ {
+	for range 2 {
 		err := pats.Load(".stignore")
 		if err == nil {
 			t.Fatal("expected an error")
diff --git a/lib/model/blockpullreorderer.go b/lib/model/blockpullreorderer.go
index d566972e2..ccdd1c182 100644
--- a/lib/model/blockpullreorderer.go
+++ b/lib/model/blockpullreorderer.go
@@ -47,7 +47,7 @@ func (randomOrderBlockPullReorderer) Reorder(blocks []protocol.BlockInfo) []prot
 type standardBlockPullReorderer struct {
 	myIndex int
 	count   int
-	shuffle func(interface{}) // Used for test
+	shuffle func(any) // Used for test
 }
 
 func newStandardBlockPullReorderer(id protocol.DeviceID, otherDevices []protocol.DeviceID) *standardBlockPullReorderer {
@@ -116,10 +116,7 @@ func chunk(blocks []protocol.BlockInfo, partCount int) [][]protocol.BlockInfo {
 	chunkSize := (count + partCount - 1) / partCount
 	parts := make([][]protocol.BlockInfo, 0, partCount)
 	for i := 0; i < count; i += chunkSize {
-		end := i + chunkSize
-		if end > count {
-			end = count
-		}
+		end := min(i+chunkSize, count)
 		parts = append(parts, blocks[i:end])
 	}
 	return parts
diff --git a/lib/model/blockpullreorderer_test.go b/lib/model/blockpullreorderer_test.go
index ac24fdeb0..beb4afde3 100644
--- a/lib/model/blockpullreorderer_test.go
+++ b/lib/model/blockpullreorderer_test.go
@@ -92,7 +92,7 @@ func Test_standardBlockPullReorderer_Reorder(t *testing.T) {
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			p := newStandardBlockPullReorderer(tt.myId, tt.devices)
-			p.shuffle = func(i interface{}) {} // Noop shuffle
+			p.shuffle = func(i any) {} // Noop shuffle
 			if got := p.Reorder(tt.blocks); !reflect.DeepEqual(got, tt.want) {
 				t.Errorf("reorderBlocksForDevices() = %v, want %v (my idx: %d, count %d)", got, tt.want, p.myIndex, p.count)
 			}
diff --git a/lib/model/folder.go b/lib/model/folder.go
index 9f9f57289..4ea6d5567 100644
--- a/lib/model/folder.go
+++ b/lib/model/folder.go
@@ -1164,7 +1164,7 @@ func (f *folder) setWatchError(err error, nextTryIn time.Duration) {
 	f.watchErr = err
 	f.watchMut.Unlock()
 	if err != prevErr { //nolint:errorlint
-		data := map[string]interface{}{
+		data := map[string]any{
 			"folder": f.ID,
 		}
 		if prevErr != nil {
@@ -1338,7 +1338,7 @@ func (f *folder) updateLocals(fs []protocol.FileInfo) error {
 	if err != nil {
 		return err
 	}
-	f.evLogger.Log(events.LocalIndexUpdated, map[string]interface{}{
+	f.evLogger.Log(events.LocalIndexUpdated, map[string]any{
 		"folder":    f.ID,
 		"items":     len(fs),
 		"filenames": filenames,
diff --git a/lib/model/folder_sendrecv.go b/lib/model/folder_sendrecv.go
index 316cb8bf7..87e1656c5 100644
--- a/lib/model/folder_sendrecv.go
+++ b/lib/model/folder_sendrecv.go
@@ -229,7 +229,7 @@ func (f *sendReceiveFolder) pull(ctx context.Context) (bool, error) {
 	f.errorsMut.Unlock()
 
 	if pullErrNum > 0 {
-		f.evLogger.Log(events.FolderErrors, map[string]interface{}{
+		f.evLogger.Log(events.FolderErrors, map[string]any{
 			"folder": f.folderID,
 			"errors": f.Errors(),
 		})
@@ -564,7 +564,7 @@ func (f *sendReceiveFolder) handleDir(file protocol.FileInfo, dbUpdateChan chan<
 
 	defer func() {
 		slog.Info("Created or updated directory", f.LogAttr(), file.LogAttr())
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   file.Name,
 			"error":  events.Error(err),
@@ -737,7 +737,7 @@ func (f *sendReceiveFolder) handleSymlink(file protocol.FileInfo, dbUpdateChan c
 		} else {
 			slog.Info("Created or updated symlink", f.LogAttr(), file.LogAttr())
 		}
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   file.Name,
 			"error":  events.Error(err),
@@ -832,7 +832,7 @@ func (f *sendReceiveFolder) deleteDir(file protocol.FileInfo, dbUpdateChan chan<
 		} else {
 			slog.Info("Deleted directory", f.LogAttr(), file.LogAttr())
 		}
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   file.Name,
 			"error":  events.Error(err),
@@ -896,7 +896,7 @@ func (f *sendReceiveFolder) deleteFileWithCurrent(file, cur protocol.FileInfo, h
 		} else {
 			slog.Info("Deleted "+kind, f.LogAttr(), file.LogAttr())
 		}
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   file.Name,
 			"error":  events.Error(err),
@@ -981,14 +981,14 @@ func (f *sendReceiveFolder) renameFile(cur, source, target protocol.FileInfo, db
 		} else {
 			slog.Info("Renamed file", f.LogAttr(), target.LogAttr(), slog.String("from", source.Name))
 		}
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   source.Name,
 			"error":  events.Error(err),
 			"type":   "file",
 			"action": "delete",
 		})
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   target.Name,
 			"error":  events.Error(err),
@@ -1275,7 +1275,7 @@ func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan ch
 		} else {
 			slog.Info("Updated file metadata", f.LogAttr(), file.LogAttr())
 		}
-		f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+		f.evLogger.Log(events.ItemFinished, map[string]any{
 			"folder": f.folderID,
 			"item":   file.Name,
 			"error":  events.Error(err),
@@ -1748,7 +1748,7 @@ func (f *sendReceiveFolder) finisherRoutine(ctx context.Context, in <-chan *shar
 				f.model.progressEmitter.Deregister(state)
 			}
 
-			f.evLogger.Log(events.ItemFinished, map[string]interface{}{
+			f.evLogger.Log(events.ItemFinished, map[string]any{
 				"folder": f.folderID,
 				"item":   state.file.Name,
 				"error":  events.Error(err),
diff --git a/lib/model/folder_sendrecv_test.go b/lib/model/folder_sendrecv_test.go
index 1daba2c5c..4e2f94445 100644
--- a/lib/model/folder_sendrecv_test.go
+++ b/lib/model/folder_sendrecv_test.go
@@ -251,7 +251,7 @@ func TestCopierFinder(t *testing.T) {
 
 	timeout := time.After(10 * time.Second)
 	pulls := make([]pullBlockState, 4)
-	for i := 0; i < 4; i++ {
+	for i := range 4 {
 		select {
 		case pulls[i] = <-pullChan:
 		case <-timeout:
@@ -408,7 +408,7 @@ func TestDeregisterOnFailInCopy(t *testing.T) {
 		t0 := time.Now()
 		if ev, err := s.Poll(time.Minute); err != nil {
 			t.Fatal("Got error waiting for ItemFinished event:", err)
-		} else if n := ev.Data.(map[string]interface{})["item"]; n != state.file.Name {
+		} else if n := ev.Data.(map[string]any)["item"]; n != state.file.Name {
 			t.Fatal("Got ItemFinished event for wrong file:", n)
 		}
 		t.Log("event took", time.Since(t0))
@@ -513,7 +513,7 @@ func TestDeregisterOnFailInPull(t *testing.T) {
 	t0 := time.Now()
 	if ev, err := s.Poll(time.Minute); err != nil {
 		t.Fatal("Got error waiting for ItemFinished event:", err)
-	} else if n := ev.Data.(map[string]interface{})["item"]; n != state.file.Name {
+	} else if n := ev.Data.(map[string]any)["item"]; n != state.file.Name {
 		t.Fatal("Got ItemFinished event for wrong file:", n)
 	}
 	t.Log("event took", time.Since(t0))
@@ -899,7 +899,7 @@ func TestPullCtxCancel(t *testing.T) {
 
 	done := make(chan struct{})
 	defer close(done)
-	for i := 0; i < 2; i++ {
+	for i := range 2 {
 		go func() {
 			select {
 			case pullChan <- emptyState():
diff --git a/lib/model/folder_sendrecv_unix.go b/lib/model/folder_sendrecv_unix.go
index 978159094..02649d58f 100644
--- a/lib/model/folder_sendrecv_unix.go
+++ b/lib/model/folder_sendrecv_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package model
 
diff --git a/lib/model/folder_summary.go b/lib/model/folder_summary.go
index 40772ae1e..98fe521c7 100644
--- a/lib/model/folder_summary.go
+++ b/lib/model/folder_summary.go
@@ -265,7 +265,7 @@ func (c *folderSummaryService) processUpdate(ev events.Event) {
 		return
 
 	case events.StateChanged:
-		data := ev.Data.(map[string]interface{})
+		data := ev.Data.(map[string]any)
 		if data["to"].(string) != "idle" {
 			return
 		}
@@ -296,7 +296,7 @@ func (c *folderSummaryService) processUpdate(ev events.Event) {
 		// This folder needs to be refreshed whenever we do the next
 		// refresh.
 
-		folder = ev.Data.(map[string]interface{})["folder"].(string)
+		folder = ev.Data.(map[string]any)["folder"].(string)
 	}
 
 	c.foldersMut.Lock()
diff --git a/lib/model/folderstate.go b/lib/model/folderstate.go
index ad1a5c156..386646b5e 100644
--- a/lib/model/folderstate.go
+++ b/lib/model/folderstate.go
@@ -119,7 +119,7 @@ func (s *stateTracker) setState(newState folderState) {
 		metricFolderState.WithLabelValues(s.folderID).Set(float64(s.current))
 	}()
 
-	eventData := map[string]interface{}{
+	eventData := map[string]any{
 		"folder": s.folderID,
 		"to":     newState.String(),
 		"from":   s.current.String(),
@@ -156,7 +156,7 @@ func (s *stateTracker) setError(err error) {
 		metricFolderState.WithLabelValues(s.folderID).Set(float64(s.current))
 	}()
 
-	eventData := map[string]interface{}{
+	eventData := map[string]any{
 		"folder": s.folderID,
 		"from":   s.current.String(),
 	}
diff --git a/lib/model/indexhandler.go b/lib/model/indexhandler.go
index 60ec50175..4e1606780 100644
--- a/lib/model/indexhandler.go
+++ b/lib/model/indexhandler.go
@@ -453,7 +453,7 @@ func (s *indexHandler) receive(fs []protocol.FileInfo, update bool, op string, p
 		})
 	}
 
-	s.evLogger.Log(events.RemoteIndexUpdated, map[string]interface{}{
+	s.evLogger.Log(events.RemoteIndexUpdated, map[string]any{
 		"device":   deviceID.String(),
 		"folder":   s.folder,
 		"items":    len(fs),
diff --git a/lib/model/indexhandler_test.go b/lib/model/indexhandler_test.go
index 57a532128..ebf6a934a 100644
--- a/lib/model/indexhandler_test.go
+++ b/lib/model/indexhandler_test.go
@@ -7,7 +7,6 @@
 package model_test
 
 import (
-	"context"
 	"fmt"
 	"io"
 	"sync"
@@ -23,8 +22,7 @@ import (
 func TestIndexhandlerConcurrency(t *testing.T) {
 	// Verify that sending a lot of index update messages using the
 	// FileInfoBatch works and doesn't trigger the race detector.
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 
 	ar, aw := io.Pipe()
 	br, bw := io.Pipe()
@@ -52,7 +50,7 @@ func TestIndexhandlerConcurrency(t *testing.T) {
 	recvdBatches := 0
 	var wg sync.WaitGroup
 	m2.IndexUpdateCalls(func(_ protocol.Connection, idxUp *protocol.IndexUpdate) error {
-		for j := 0; j < files; j++ {
+		for j := range int(files) {
 			if n := idxUp.Files[j].Name; n != fmt.Sprintf("f%d-%d", recvdBatches, j) {
 				t.Error("wrong filename", n)
 			}
@@ -67,8 +65,8 @@ func TestIndexhandlerConcurrency(t *testing.T) {
 		return c1.IndexUpdate(ctx, &protocol.IndexUpdate{Folder: "foo", Files: fs})
 	})
 	sentEntries := 0
-	for i := 0; i < msgs; i++ {
-		for j := 0; j < files; j++ {
+	for i := range int(msgs) {
+		for j := range int(files) {
 			b1.Append(protocol.FileInfo{
 				Name:   fmt.Sprintf("f%d-%d", i, j),
 				Blocks: []protocol.BlockInfo{{Hash: make([]byte, 32)}},
diff --git a/lib/model/model.go b/lib/model/model.go
index 3b35a4a64..2cb8fdb4b 100644
--- a/lib/model/model.go
+++ b/lib/model/model.go
@@ -116,7 +116,7 @@ type Model interface {
 	Availability(folder string, file protocol.FileInfo, block protocol.BlockInfo) ([]Availability, error)
 
 	Completion(device protocol.DeviceID, folder string) (FolderCompletion, error)
-	ConnectionStats() map[string]interface{}
+	ConnectionStats() map[string]any
 	DeviceStatistics() (map[protocol.DeviceID]stats.DeviceStatistics, error)
 	FolderStatistics() (map[string]stats.FolderStatistics, error)
 	UsageReportingStats(report *contract.Report, version int, preview bool)
@@ -684,7 +684,7 @@ type ConnectionStats struct {
 	IsLocal bool   `json:"isLocal"` // mirror values from Primary, for compatibility with <1.24.0
 	Crypto  string `json:"crypto"`  // mirror values from Primary, for compatibility with <1.24.0
 
-	Primary   ConnectionInfo   `json:"primary,omitempty"`
+	Primary   ConnectionInfo   `json:"primary"`
 	Secondary []ConnectionInfo `json:"secondary,omitempty"`
 }
 
@@ -698,11 +698,11 @@ type ConnectionInfo struct {
 }
 
 // ConnectionStats returns a map with connection statistics for each device.
-func (m *model) ConnectionStats() map[string]interface{} {
+func (m *model) ConnectionStats() map[string]any {
 	m.mut.RLock()
 	defer m.mut.RUnlock()
 
-	res := make(map[string]interface{})
+	res := make(map[string]any)
 	devs := m.cfg.Devices()
 	conns := make(map[string]ConnectionStats, len(devs))
 	for device, deviceCfg := range devs {
@@ -762,7 +762,7 @@ func (m *model) ConnectionStats() map[string]interface{} {
 	res["connections"] = conns
 
 	in, out := protocol.TotalInOut()
-	res["total"] = map[string]interface{}{
+	res["total"] = map[string]any{
 		"at":            time.Now().Truncate(time.Second),
 		"inBytesTotal":  in,
 		"outBytesTotal": out,
@@ -862,8 +862,8 @@ func (comp *FolderCompletion) setCompletionPct() {
 }
 
 // Map returns the members as a map, e.g. used in api to serialize as JSON.
-func (comp *FolderCompletion) Map() map[string]interface{} {
-	return map[string]interface{}{
+func (comp *FolderCompletion) Map() map[string]any {
+	return map[string]any{
 		"completion":  comp.CompletionPct,
 		"globalBytes": comp.GlobalBytes,
 		"needBytes":   comp.NeedBytes,
@@ -1516,7 +1516,7 @@ func (m *model) ccHandleFolders(folders []protocol.Folder, deviceCfg config.Devi
 		})
 	}
 	if len(updatedPending) > 0 || len(expiredPendingList) > 0 {
-		m.evLogger.Log(events.PendingFoldersChanged, map[string]interface{}{
+		m.evLogger.Log(events.PendingFoldersChanged, map[string]any{
 			"added":   updatedPending,
 			"removed": expiredPendingList,
 		})
@@ -2266,7 +2266,7 @@ func (m *model) OnHello(remoteID protocol.DeviceID, addr net.Addr, hello protoco
 		if err := m.observed.AddOrUpdatePendingDevice(remoteID, hello.DeviceName, addr.String()); err != nil {
 			slog.Warn("Failed to persist pending device entry to database", slogutil.Error(err))
 		}
-		m.evLogger.Log(events.PendingDevicesChanged, map[string][]interface{}{
+		m.evLogger.Log(events.PendingDevicesChanged, map[string][]any{
 			"added": {map[string]string{
 				"deviceID": remoteID.String(),
 				"name":     hello.DeviceName,
@@ -2426,7 +2426,7 @@ func (m *model) DownloadProgress(conn protocol.Connection, p *protocol.DownloadP
 	downloads.Update(p.Folder, p.Updates)
 	state := downloads.GetBlockCounts(p.Folder)
 
-	m.evLogger.Log(events.RemoteDownloadProgress, map[string]interface{}{
+	m.evLogger.Log(events.RemoteDownloadProgress, map[string]any{
 		"device": deviceID.String(),
 		"folder": p.Folder,
 		"state":  state,
@@ -2772,7 +2772,7 @@ func (m *model) GlobalDirectoryTree(folder, prefix string, levels int, dirsOnly
 
 		parent := root
 		if dir != "." {
-			for _, path := range strings.Split(dir, sep) {
+			for path := range strings.SplitSeq(dir, sep) {
 				child := findByName(parent.Children, path)
 				if child == nil {
 					return nil, fmt.Errorf("could not find child '%s' for path '%s' in parent '%s'", path, f.Name, parent.Name)
@@ -3183,7 +3183,7 @@ func (m *model) cleanPending(existingDevices map[protocol.DeviceID]config.Device
 		}
 	}
 	if len(removedPendingFolders) > 0 {
-		m.evLogger.Log(events.PendingFoldersChanged, map[string]interface{}{
+		m.evLogger.Log(events.PendingFoldersChanged, map[string]any{
 			"removed": removedPendingFolders,
 		})
 	}
@@ -3218,7 +3218,7 @@ func (m *model) cleanPending(existingDevices map[protocol.DeviceID]config.Device
 		})
 	}
 	if len(removedPendingDevices) > 0 {
-		m.evLogger.Log(events.PendingDevicesChanged, map[string]interface{}{
+		m.evLogger.Log(events.PendingDevicesChanged, map[string]any{
 			"removed": removedPendingDevices,
 		})
 	}
@@ -3264,7 +3264,7 @@ func (m *model) DismissPendingDevice(device protocol.DeviceID) error {
 	removedPendingDevices := []map[string]string{
 		{"deviceID": device.String()},
 	}
-	m.evLogger.Log(events.PendingDevicesChanged, map[string]interface{}{
+	m.evLogger.Log(events.PendingDevicesChanged, map[string]any{
 		"removed": removedPendingDevices,
 	})
 	return nil
@@ -3298,7 +3298,7 @@ func (m *model) DismissPendingFolder(device protocol.DeviceID, folder string) er
 		}
 	}
 	if len(removedPendingFolders) > 0 {
-		m.evLogger.Log(events.PendingFoldersChanged, map[string]interface{}{
+		m.evLogger.Log(events.PendingFoldersChanged, map[string]any{
 			"removed": removedPendingFolders,
 		})
 	}
diff --git a/lib/model/model_test.go b/lib/model/model_test.go
index 8cac582eb..1b144ff54 100644
--- a/lib/model/model_test.go
+++ b/lib/model/model_test.go
@@ -151,7 +151,7 @@ func TestRequest(t *testing.T) {
 func genFiles(n int) []protocol.FileInfo {
 	files := make([]protocol.FileInfo, n)
 	t := time.Now().Unix()
-	for i := 0; i < n; i++ {
+	for i := range n {
 		files[i] = protocol.FileInfo{
 			Name:      fmt.Sprintf("file%d", i),
 			ModifiedS: t,
@@ -1007,7 +1007,7 @@ func TestIssue5063(t *testing.T) {
 
 	reps := 10
 	ids := make([]string, reps)
-	for i := 0; i < reps; i++ {
+	for i := range reps {
 		ids[i] = srand.String(8)
 		wg.Go(func() { addAndVerify(ids[i]) })
 	}
@@ -1668,7 +1668,7 @@ func waitForState(t *testing.T, sub events.Subscription, folder, expected string
 	for {
 		select {
 		case ev := <-sub.C():
-			data := ev.Data.(map[string]interface{})
+			data := ev.Data.(map[string]any)
 			if data["folder"].(string) == folder {
 				if data["error"] == nil {
 					err = ""
@@ -1880,7 +1880,7 @@ func TestGlobalDirectoryTree(t *testing.T) {
 		f("zzrootfile"),
 	}
 
-	mm := func(data interface{}) string {
+	mm := func(data any) string {
 		bytes, err := json.MarshalIndent(data, "", "  ")
 		if err != nil {
 			panic(err)
@@ -2952,7 +2952,7 @@ func TestFolderRestartZombies(t *testing.T) {
 	// Run a few parallel configuration changers for one second. Each waits
 	// for the commit to complete, but there are many of them.
 	var wg sync.WaitGroup
-	for i := 0; i < 25; i++ {
+	for range 25 {
 		wg.Go(func() {
 			t0 := time.Now()
 			for time.Since(t0) < time.Second {
@@ -3258,7 +3258,7 @@ func TestRenameSequenceOrder(t *testing.T) {
 	numFiles := 20
 
 	ffs := fcfg.Filesystem()
-	for i := 0; i < numFiles; i++ {
+	for i := range numFiles {
 		v := fmt.Sprintf("%d", i)
 		writeFile(t, ffs, v, []byte(v))
 	}
@@ -3272,7 +3272,7 @@ func TestRenameSequenceOrder(t *testing.T) {
 
 	// Modify all the files other than the rename sources, whose content we
 	// keep intact so the renamed copies still match by block hash.
-	for i := 0; i < numFiles; i++ {
+	for i := range numFiles {
 		if i == 3 || i == 16 {
 			continue
 		}
@@ -3388,7 +3388,7 @@ func TestRenameBatchFlush(t *testing.T) {
 	writeFile(t, ffs, "dst-a", content)
 	writeFile(t, ffs, "dst-b", content)
 	for i := range MaxBatchSizeFiles * 2 {
-		writeFile(t, ffs, fmt.Sprintf("filler-%04d", i), []byte(fmt.Sprintf("filler-%04d", i)))
+		writeFile(t, ffs, fmt.Sprintf("filler-%04d", i), fmt.Appendf(nil, "filler-%04d", i))
 	}
 
 	m.ScanFolders()
diff --git a/lib/model/queue_test.go b/lib/model/queue_test.go
index d8467ff4d..3dce98846 100644
--- a/lib/model/queue_test.go
+++ b/lib/model/queue_test.go
@@ -200,7 +200,7 @@ func TestQueuePagination(t *testing.T) {
 	q := newJobQueue()
 	// Ten random actions
 	names := make([]string, 10)
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		names[i] = fmt.Sprint("f", i)
 		q.Push(names[i], 0, time.Time{})
 	}
diff --git a/lib/model/requests_test.go b/lib/model/requests_test.go
index 288140721..c4e7fdc34 100644
--- a/lib/model/requests_test.go
+++ b/lib/model/requests_test.go
@@ -582,7 +582,7 @@ func TestRequestSymlinkWindows(t *testing.T) {
 	for {
 		select {
 		case ev := <-sub.C():
-			switch data := ev.Data.(map[string]interface{}); {
+			switch data := ev.Data.(map[string]any); {
 			case ev.Type == events.LocalIndexUpdated:
 				t.Fatalf("Local index was updated unexpectedly: %v", data)
 			case ev.Type == events.StateChanged:
@@ -927,7 +927,7 @@ func TestNeedFolderFiles(t *testing.T) {
 
 	data := []byte("foo")
 	num := 20
-	for i := 0; i < num; i++ {
+	for i := range num {
 		fc.addFile(strconv.Itoa(i), 0o644, protocol.FileInfoTypeFile, data)
 	}
 	fc.sendIndexUpdate()
diff --git a/lib/model/testos_test.go b/lib/model/testos_test.go
index b7110ef75..474489226 100644
--- a/lib/model/testos_test.go
+++ b/lib/model/testos_test.go
@@ -8,7 +8,7 @@ package model
 
 // fatal is the required common interface between *testing.B and *testing.T
 type fatal interface {
-	Fatal(...interface{})
+	Fatal(...any)
 	Helper()
 }
 
diff --git a/lib/model/testutils_test.go b/lib/model/testutils_test.go
index b9f6376c7..bbec56cf5 100644
--- a/lib/model/testutils_test.go
+++ b/lib/model/testutils_test.go
@@ -284,7 +284,7 @@ func localIndexUpdate(m *testModel, folder string, fs []protocol.FileInfo) {
 	for i, file := range fs {
 		filenames[i] = file.Name
 	}
-	m.evLogger.Log(events.LocalIndexUpdated, map[string]interface{}{
+	m.evLogger.Log(events.LocalIndexUpdated, map[string]any{
 		"folder":    folder,
 		"items":     len(fs),
 		"filenames": filenames,
diff --git a/lib/osutil/atomic_unix_test.go b/lib/osutil/atomic_unix_test.go
index 804b2d8dd..d9e178001 100644
--- a/lib/osutil/atomic_unix_test.go
+++ b/lib/osutil/atomic_unix_test.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 // (No syscall.Umask or the equivalent on Windows)
 
diff --git a/lib/osutil/filenames_unix.go b/lib/osutil/filenames_unix.go
index 5fab42520..23bbcdb5e 100644
--- a/lib/osutil/filenames_unix.go
+++ b/lib/osutil/filenames_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows && !darwin
-// +build !windows,!darwin
 
 package osutil
 
diff --git a/lib/osutil/hidden_unix.go b/lib/osutil/hidden_unix.go
index 0602aff42..c91a0c646 100644
--- a/lib/osutil/hidden_unix.go
+++ b/lib/osutil/hidden_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package osutil
 
diff --git a/lib/osutil/hidden_windows.go b/lib/osutil/hidden_windows.go
index 9a7d143a6..6c0986bf6 100644
--- a/lib/osutil/hidden_windows.go
+++ b/lib/osutil/hidden_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package osutil
 
diff --git a/lib/osutil/lowprio_linux.go b/lib/osutil/lowprio_linux.go
index a76500ab6..746519c9e 100644
--- a/lib/osutil/lowprio_linux.go
+++ b/lib/osutil/lowprio_linux.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !android
-// +build !android
 
 package osutil
 
diff --git a/lib/osutil/lowprio_noop.go b/lib/osutil/lowprio_noop.go
index 41f275744..e6ae36316 100644
--- a/lib/osutil/lowprio_noop.go
+++ b/lib/osutil/lowprio_noop.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build ios
-// +build ios
 
 package osutil
 
diff --git a/lib/osutil/lowprio_unix.go b/lib/osutil/lowprio_unix.go
index deb7d2342..e5b21b755 100644
--- a/lib/osutil/lowprio_unix.go
+++ b/lib/osutil/lowprio_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build (!windows && !linux && !ios) || android
-// +build !windows,!linux,!ios android
 
 package osutil
 
diff --git a/lib/osutil/rlimit_unix.go b/lib/osutil/rlimit_unix.go
index 492ce2a7e..ab439f447 100644
--- a/lib/osutil/rlimit_unix.go
+++ b/lib/osutil/rlimit_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package osutil
 
diff --git a/lib/osutil/rlimit_windows.go b/lib/osutil/rlimit_windows.go
index 7a7606336..748b23d39 100644
--- a/lib/osutil/rlimit_windows.go
+++ b/lib/osutil/rlimit_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package osutil
 
diff --git a/lib/protocol/bufferpool_test.go b/lib/protocol/bufferpool_test.go
index 081725988..3b9ac09d7 100644
--- a/lib/protocol/bufferpool_test.go
+++ b/lib/protocol/bufferpool_test.go
@@ -81,7 +81,7 @@ func TestStressBufferPool(t *testing.T) {
 
 	var wg sync.WaitGroup
 	fail := make(chan struct{}, routines)
-	for i := 0; i < routines; i++ {
+	for range routines {
 		wg.Go(func() {
 			for time.Since(t0) < runtime {
 				blocks := make([][]byte, 10)
diff --git a/lib/protocol/encryption.go b/lib/protocol/encryption.go
index 7c1ccaa65..27e3e021d 100644
--- a/lib/protocol/encryption.go
+++ b/lib/protocol/encryption.go
@@ -211,12 +211,10 @@ func (e encryptedConnection) Request(ctx context.Context, req *Request) ([]byte,
 
 	// Encrypt / adjust the request parameters.
 
-	encSize := req.Size
-	if encSize < minPaddedSize {
+	encSize := max(req.Size,
 		// Make a request for minPaddedSize data instead of the smaller
 		// block. We'll chop of the extra data later.
-		encSize = minPaddedSize
-	}
+		minPaddedSize)
 	encSize += blockOverhead
 	encName := encryptName(req.Name, folderKey)
 	encOffset := req.Offset + int64(req.BlockNo*blockOverhead)
diff --git a/lib/protocol/encryption_test.go b/lib/protocol/encryption_test.go
index a66683583..1c4577238 100644
--- a/lib/protocol/encryption_test.go
+++ b/lib/protocol/encryption_test.go
@@ -56,7 +56,7 @@ func TestEnDecryptName(t *testing.T) {
 	}
 	for _, tc := range cases {
 		var prev string
-		for i := 0; i < 5; i++ {
+		for range 5 {
 			enc := encryptName(tc, &key)
 			if prev != "" && prev != enc {
 				t.Error("name should always encrypt the same")
@@ -124,7 +124,7 @@ func TestEnDecryptBytes(t *testing.T) {
 	}
 	for _, tc := range cases {
 		var prev []byte
-		for i := 0; i < 5; i++ {
+		for range 5 {
 			enc := encryptBytes(tc, &key)
 			if bytes.Equal(enc, prev) {
 				t.Error("encryption should not repeat")
diff --git a/lib/protocol/nativemodel_darwin.go b/lib/protocol/nativemodel_darwin.go
index 7d1f06900..11a4b13ae 100644
--- a/lib/protocol/nativemodel_darwin.go
+++ b/lib/protocol/nativemodel_darwin.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build darwin
-// +build darwin
 
 package protocol
 
diff --git a/lib/protocol/nativemodel_unix.go b/lib/protocol/nativemodel_unix.go
index 46c4e77da..30a386a3a 100644
--- a/lib/protocol/nativemodel_unix.go
+++ b/lib/protocol/nativemodel_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows && !darwin
-// +build !windows,!darwin
 
 package protocol
 
diff --git a/lib/protocol/nativemodel_windows.go b/lib/protocol/nativemodel_windows.go
index 96c6dd57b..f194b83c1 100644
--- a/lib/protocol/nativemodel_windows.go
+++ b/lib/protocol/nativemodel_windows.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build windows
-// +build windows
 
 package protocol
 
diff --git a/lib/protocol/protocol_test.go b/lib/protocol/protocol_test.go
index 6ac5175c2..2c57f89f4 100644
--- a/lib/protocol/protocol_test.go
+++ b/lib/protocol/protocol_test.go
@@ -310,7 +310,7 @@ func TestWriteCompressed(t *testing.T) {
 }
 
 func TestLZ4Compression(t *testing.T) {
-	for i := 0; i < 10; i++ {
+	for i := range 10 {
 		dataLen := 150 + rand.Intn(150)
 		data := make([]byte, dataLen)
 		_, err := io.ReadFull(rand.Reader, data[100:])
@@ -716,7 +716,7 @@ func TestIndexIDString(t *testing.T) {
 	}
 }
 
-func closeAndWait(c interface{}, closers ...io.Closer) {
+func closeAndWait(c any, closers ...io.Closer) {
 	for _, closer := range closers {
 		closer.Close()
 	}
diff --git a/lib/rand/random.go b/lib/rand/random.go
index 0e4f0c5cc..45548b132 100644
--- a/lib/rand/random.go
+++ b/lib/rand/random.go
@@ -64,7 +64,7 @@ func Intn(n int) int {
 }
 
 // Shuffle the order of elements in slice.
-func Shuffle(slice interface{}) {
+func Shuffle(slice any) {
 	rv := reflect.ValueOf(slice)
 	swap := reflect.Swapper(slice)
 	length := rv.Len()
diff --git a/lib/rc/rc.go b/lib/rc/rc.go
index 7deff4c3d..46c5ba100 100644
--- a/lib/rc/rc.go
+++ b/lib/rc/rc.go
@@ -218,7 +218,7 @@ type Event struct {
 	ID   int
 	Time time.Time
 	Type string
-	Data interface{}
+	Data any
 }
 
 func (p *Process) Events(since int) ([]Event, error) {
@@ -490,7 +490,7 @@ func (p *Process) eventLoop() {
 				// The Starting event tells us where the configuration is. Load
 				// it and populate our list of folders.
 
-				data := ev.Data.(map[string]interface{})
+				data := ev.Data.(map[string]any)
 				id, err := protocol.DeviceIDFromString(data["myID"].(string))
 				if err != nil {
 					log.Println("eventLoop: DeviceIdFromString:", err)
@@ -525,7 +525,7 @@ func (p *Process) eventLoop() {
 				select {
 				case <-p.startComplete:
 				default:
-					data := ev.Data.(map[string]interface{})
+					data := ev.Data.(map[string]any)
 					to := data["to"].(string)
 					if to == "idle" {
 						folder := data["folder"].(string)
@@ -537,7 +537,7 @@ func (p *Process) eventLoop() {
 				}
 
 			case "LocalIndexUpdated":
-				data := ev.Data.(map[string]interface{})
+				data := ev.Data.(map[string]any)
 				folder := data["folder"].(string)
 				p.eventMut.Lock()
 				m := p.updateSequenceLocked(folder, p.id.String(), data["sequence"])
@@ -546,7 +546,7 @@ func (p *Process) eventLoop() {
 				p.eventMut.Unlock()
 
 			case "RemoteIndexUpdated":
-				data := ev.Data.(map[string]interface{})
+				data := ev.Data.(map[string]any)
 				device := data["device"].(string)
 				folder := data["folder"].(string)
 				p.eventMut.Lock()
@@ -556,9 +556,9 @@ func (p *Process) eventLoop() {
 				p.eventMut.Unlock()
 
 			case "FolderSummary":
-				data := ev.Data.(map[string]interface{})
+				data := ev.Data.(map[string]any)
 				folder := data["folder"].(string)
-				summary := data["summary"].(map[string]interface{})
+				summary := data["summary"].(map[string]any)
 				need, _ := summary["needTotalItems"].(json.Number).Int64()
 				done := need == 0
 				p.eventMut.Lock()
@@ -568,7 +568,7 @@ func (p *Process) eventLoop() {
 				p.eventMut.Unlock()
 
 			case "FolderCompletion":
-				data := ev.Data.(map[string]interface{})
+				data := ev.Data.(map[string]any)
 				device := data["device"].(string)
 				folder := data["folder"].(string)
 				p.eventMut.Lock()
@@ -580,7 +580,7 @@ func (p *Process) eventLoop() {
 	}
 }
 
-func (p *Process) updateSequenceLocked(folder, device string, sequenceIntf interface{}) map[string]int64 {
+func (p *Process) updateSequenceLocked(folder, device string, sequenceIntf any) map[string]int64 {
 	sequence, _ := sequenceIntf.(json.Number).Int64()
 	m := p.sequence[folder]
 	if m == nil {
diff --git a/lib/relay/client/static.go b/lib/relay/client/static.go
index 081491f68..f32948779 100644
--- a/lib/relay/client/static.go
+++ b/lib/relay/client/static.go
@@ -69,7 +69,7 @@ func (c *staticClient) serve(ctx context.Context) error {
 
 	slog.InfoContext(ctx, "Joined relay", slogutil.URI(fmt.Sprintf("%s://%s", c.uri.Scheme, c.uri.Host)))
 
-	messages := make(chan interface{})
+	messages := make(chan any)
 	errorsc := make(chan error, 1)
 
 	go messageReader(ctx, c.conn, messages, errorsc)
@@ -235,7 +235,7 @@ func performHandshakeAndValidation(conn *tls.Conn, uri *url.URL) error {
 	return nil
 }
 
-func messageReader(ctx context.Context, conn net.Conn, messages chan<- interface{}, errors chan<- error) {
+func messageReader(ctx context.Context, conn net.Conn, messages chan<- any, errors chan<- error) {
 	for {
 		msg, err := protocol.ReadMessage(conn)
 		if err != nil {
diff --git a/lib/relay/protocol/protocol.go b/lib/relay/protocol/protocol.go
index a4eb4d8d5..dc905cf65 100644
--- a/lib/relay/protocol/protocol.go
+++ b/lib/relay/protocol/protocol.go
@@ -21,7 +21,7 @@ var (
 	ResponseUnexpectedMessage = Response{100, "unexpected message"}
 )
 
-func WriteMessage(w io.Writer, message interface{}) error {
+func WriteMessage(w io.Writer, message any) error {
 	header := header{
 		magic: magic,
 	}
@@ -73,7 +73,7 @@ func WriteMessage(w io.Writer, message interface{}) error {
 	return err
 }
 
-func ReadMessage(r io.Reader) (interface{}, error) {
+func ReadMessage(r io.Reader) (any, error) {
 	var header header
 
 	buf := make([]byte, header.XDRSize())
diff --git a/lib/scanner/blocks_test.go b/lib/scanner/blocks_test.go
index b54eb4f74..5ec77be2f 100644
--- a/lib/scanner/blocks_test.go
+++ b/lib/scanner/blocks_test.go
@@ -122,7 +122,7 @@ func BenchmarkValidate(b *testing.B) {
 	r := mrand.New(mrand.NewSource(0x136bea689e851))
 
 	// Valid blocks.
-	for i := 0; i < blocksPerType; i++ {
+	for range blocksPerType {
 		var b block
 		b.data = make([]byte, 128<<10)
 		r.Read(b.data)
diff --git a/lib/scanner/virtualfs_test.go b/lib/scanner/virtualfs_test.go
index 5617b5441..ce828b61e 100644
--- a/lib/scanner/virtualfs_test.go
+++ b/lib/scanner/virtualfs_test.go
@@ -125,7 +125,7 @@ func (f fakeInfo) IsRegular() bool { return !f.IsDir() }
 func (fakeInfo) IsSymlink() bool   { return false }
 func (fakeInfo) Owner() int        { return 0 }
 func (fakeInfo) Group() int        { return 0 }
-func (fakeInfo) Sys() interface{}  { return nil }
+func (fakeInfo) Sys() any          { return nil }
 
 type fakeFile struct {
 	name       string
diff --git a/lib/scanner/walk.go b/lib/scanner/walk.go
index 2b8bfb5d4..105307df2 100644
--- a/lib/scanner/walk.go
+++ b/lib/scanner/walk.go
@@ -181,7 +181,7 @@ func (w *walker) walk(ctx context.Context) chan ScanResult {
 				current := progress.Total()
 				rate := progress.Rate()
 				l.Debugf("%v: Walk %s %s current progress %d/%d at %.01f MiB/s (%d%%)", w, w.Folder, w.Subs, current, total, rate/1024/1024, current*100/total)
-				w.EventLogger.Log(events.FolderScanProgress, map[string]interface{}{
+				w.EventLogger.Log(events.FolderScanProgress, map[string]any{
 					"folder":  w.Folder,
 					"current": current,
 					"total":   total,
diff --git a/lib/scanner/walk_test.go b/lib/scanner/walk_test.go
index c669a4457..3acf9da95 100644
--- a/lib/scanner/walk_test.go
+++ b/lib/scanner/walk_test.go
@@ -979,11 +979,11 @@ func testConfig() (Config, context.CancelFunc) {
 func BenchmarkWalk(b *testing.B) {
 	testFs := fs.NewFilesystem(fs.FilesystemTypeFake, rand.String(32))
 
-	for i := 0; i < 100; i++ {
+	for i := range 100 {
 		if err := testFs.Mkdir(fmt.Sprintf("dir%d", i), 0o755); err != nil {
 			b.Fatal(err)
 		}
-		for j := 0; j < 100; j++ {
+		for j := range 100 {
 			if fd, err := testFs.Create(fmt.Sprintf("dir%d/file%d", i, j)); err != nil {
 				b.Fatal(err)
 			} else {
diff --git a/lib/structutil/structutil.go b/lib/structutil/structutil.go
index b84e89924..8ec94f1b5 100644
--- a/lib/structutil/structutil.go
+++ b/lib/structutil/structutil.go
@@ -100,7 +100,7 @@ func fillNil(data any, skipDeprecated bool) {
 
 		f := s.Field(i)
 
-		for f.Kind() == reflect.Ptr && f.IsZero() && f.CanSet() {
+		for f.Kind() == reflect.Pointer && f.IsZero() && f.CanSet() {
 			newValue := reflect.New(f.Type().Elem())
 			f.Set(newValue)
 			f = f.Elem()
@@ -157,7 +157,7 @@ func FillNilSlices(data any) error {
 						vs[i] = strings.TrimSpace(vs[i])
 					}
 
-					rv := reflect.MakeSlice(reflect.TypeOf([]string{}), len(vs), len(vs))
+					rv := reflect.MakeSlice(reflect.TypeFor[[]string](), len(vs), len(vs))
 					for i, v := range vs {
 						rv.Index(i).SetString(v)
 					}
diff --git a/lib/syncthing/superuser_unix.go b/lib/syncthing/superuser_unix.go
index 4e7603422..385dd5c7c 100644
--- a/lib/syncthing/superuser_unix.go
+++ b/lib/syncthing/superuser_unix.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !windows
-// +build !windows
 
 package syncthing
 
diff --git a/lib/syncthing/syncthing.go b/lib/syncthing/syncthing.go
index 1f3664285..f53221291 100644
--- a/lib/syncthing/syncthing.go
+++ b/lib/syncthing/syncthing.go
@@ -458,7 +458,7 @@ func printServiceTree(w io.Writer, sup supervisor, level int) {
 	}
 }
 
-func printService(w io.Writer, svc interface{}, level int) {
+func printService(w io.Writer, svc any, level int) {
 	type errorer interface{ Error() error }
 
 	t := "-"
diff --git a/lib/syncutil/timeoutcond_test.go b/lib/syncutil/timeoutcond_test.go
index 65135ab18..a98b9adf7 100644
--- a/lib/syncutil/timeoutcond_test.go
+++ b/lib/syncutil/timeoutcond_test.go
@@ -34,7 +34,7 @@ func TestTimeoutCond(t *testing.T) {
 	go func() {
 		d := time.Duration(routines) * timeMult * time.Millisecond / 2
 		t.Log("Broadcasting every", d)
-		for i := 0; i < iterations; i++ {
+		for range iterations {
 			time.Sleep(d)
 
 			c.L.Lock()
@@ -47,7 +47,7 @@ func TestTimeoutCond(t *testing.T) {
 
 	var results [routines][2]int
 	var wg sync.WaitGroup
-	for i := 0; i < routines; i++ {
+	for i := range routines {
 		wg.Go(func() {
 			d := time.Duration(i) * timeMult * time.Millisecond
 			t.Logf("Routine %d waits for %v\n", i, d)
@@ -67,7 +67,7 @@ func TestTimeoutCond(t *testing.T) {
 }
 
 func runLocks(t *testing.T, iterations int, c *TimeoutCond, d time.Duration) (succ, fail int) {
-	for i := 0; i < iterations; i++ {
+	for range iterations {
 		c.L.Lock()
 
 		// The thread may be stalled, so we can't test the 'succeeded late' case reliably.
diff --git a/lib/tlsutil/tlsutil.go b/lib/tlsutil/tlsutil.go
index 62c93f45e..b758ce1a7 100644
--- a/lib/tlsutil/tlsutil.go
+++ b/lib/tlsutil/tlsutil.go
@@ -264,7 +264,7 @@ func (c *UnionedConnection) Read(b []byte) (n int, err error) {
 	return c.Conn.Read(b)
 }
 
-func pemBlockForKey(priv interface{}) (*pem.Block, error) {
+func pemBlockForKey(priv any) (*pem.Block, error) {
 	switch k := priv.(type) {
 	case *rsa.PrivateKey:
 		return &pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(k)}, nil
diff --git a/lib/upgrade/upgrade_common.go b/lib/upgrade/upgrade_common.go
index b0483546f..69fbd618a 100644
--- a/lib/upgrade/upgrade_common.go
+++ b/lib/upgrade/upgrade_common.go
@@ -211,7 +211,7 @@ func CompareVersions(a, b string) Relation {
 
 // Split a version into parts.
 // "1.2.3-beta.2" -> []int{1, 2, 3}, []interface{}{"beta", 2}
-func versionParts(v string) ([]int, []interface{}) {
+func versionParts(v string) ([]int, []any) {
 	if strings.HasPrefix(v, "v") || strings.HasPrefix(v, "V") {
 		// Strip initial 'v' or 'V' prefix if present.
 		v = v[1:]
@@ -226,10 +226,10 @@ func versionParts(v string) ([]int, []interface{}) {
 		release[i] = v
 	}
 
-	var prerelease []interface{}
+	var prerelease []any
 	if len(parts) > 1 {
 		fields = strings.Split(parts[1], ".")
-		prerelease = make([]interface{}, len(fields))
+		prerelease = make([]any, len(fields))
 		for i, s := range fields {
 			v, err := strconv.Atoi(s)
 			if err == nil {
diff --git a/lib/upgrade/upgrade_supported.go b/lib/upgrade/upgrade_supported.go
index fc236af52..92994bbb5 100644
--- a/lib/upgrade/upgrade_supported.go
+++ b/lib/upgrade/upgrade_supported.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !noupgrade && !ios
-// +build !noupgrade,!ios
 
 package upgrade
 
diff --git a/lib/upgrade/upgrade_test.go b/lib/upgrade/upgrade_test.go
index 919af72c1..55df80e18 100644
--- a/lib/upgrade/upgrade_test.go
+++ b/lib/upgrade/upgrade_test.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build !noupgrade
-// +build !noupgrade
 
 package upgrade
 
diff --git a/lib/upgrade/upgrade_unsupp.go b/lib/upgrade/upgrade_unsupp.go
index f8d922279..40a8d1598 100644
--- a/lib/upgrade/upgrade_unsupp.go
+++ b/lib/upgrade/upgrade_unsupp.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build noupgrade || ios
-// +build noupgrade ios
 
 package upgrade
 
diff --git a/lib/upnp/upnp.go b/lib/upnp/upnp.go
index 04086a7ec..292baa27d 100644
--- a/lib/upnp/upnp.go
+++ b/lib/upnp/upnp.go
@@ -275,7 +275,6 @@ loop:
 			continue
 		}
 		for _, igd := range igds {
-			igd := igd // Copy before sending pointer to the channel.
 			select {
 			case results <- &igd:
 			case <-ctx.Done():
diff --git a/lib/ur/contract/contract.go b/lib/ur/contract/contract.go
index 37cebf331..3e0c5821e 100644
--- a/lib/ur/contract/contract.go
+++ b/lib/ur/contract/contract.go
@@ -232,7 +232,7 @@ func (r Report) Value() (driver.Value, error) {
 	return string(bs), err
 }
 
-func (r *Report) Scan(value interface{}) error {
+func (r *Report) Scan(value any) error {
 	// Zero out the previous value
 	// JSON un-marshaller does not touch fields that are not in the payload, so we carry over values from a previous
 	// scan.
@@ -245,7 +245,7 @@ func (r *Report) Scan(value interface{}) error {
 	return json.Unmarshal(b, &r)
 }
 
-func clear(v interface{}, since int) error {
+func clear(v any, since int) error {
 	s := reflect.ValueOf(v).Elem()
 	t := s.Type()
 
@@ -269,7 +269,7 @@ func clear(v interface{}, since int) error {
 		}
 
 		// Dive deeper
-		if f.Kind() == reflect.Ptr {
+		if f.Kind() == reflect.Pointer {
 			f = f.Elem()
 		}
 
diff --git a/lib/ur/contract/contract_test.go b/lib/ur/contract/contract_test.go
index 7cf9f2ce3..2534ac67b 100644
--- a/lib/ur/contract/contract_test.go
+++ b/lib/ur/contract/contract_test.go
@@ -118,7 +118,7 @@ func TestClean(t *testing.T) {
 	expect(t, 6, x)
 }
 
-func expect(t *testing.T, since int, b interface{}) {
+func expect(t *testing.T, since int, b any) {
 	t.Helper()
 	x := testValue()
 	if err := clear(&x, since); err != nil {
diff --git a/lib/ur/memsize_solaris.go b/lib/ur/memsize_solaris.go
index 4614dad33..ea009cb74 100644
--- a/lib/ur/memsize_solaris.go
+++ b/lib/ur/memsize_solaris.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build solaris
-// +build solaris
 
 package ur
 
diff --git a/lib/ur/memsize_unimpl.go b/lib/ur/memsize_unimpl.go
index d1c576c80..44809796f 100644
--- a/lib/ur/memsize_unimpl.go
+++ b/lib/ur/memsize_unimpl.go
@@ -5,7 +5,6 @@
 // You can obtain one at https://mozilla.org/MPL/2.0/.
 
 //go:build freebsd || openbsd || dragonfly
-// +build freebsd openbsd dragonfly
 
 package ur
 
diff --git a/lib/watchaggregator/aggregator.go b/lib/watchaggregator/aggregator.go
index bfb2c4e9a..4ab439702 100644
--- a/lib/watchaggregator/aggregator.go
+++ b/lib/watchaggregator/aggregator.go
@@ -454,7 +454,7 @@ func updateInProgressSet(event events.Event, inProgress map[string]struct{}) {
 		path := event.Data.(map[string]string)["item"]
 		inProgress[path] = struct{}{}
 	case events.ItemFinished:
-		path := event.Data.(map[string]interface{})["item"].(string)
+		path := event.Data.(map[string]any)["item"].(string)
 		delete(inProgress, path)
 	}
 }
diff --git a/lib/watchaggregator/aggregator_test.go b/lib/watchaggregator/aggregator_test.go
index 681c372f8..cb67c6f5c 100644
--- a/lib/watchaggregator/aggregator_test.go
+++ b/lib/watchaggregator/aggregator_test.go
@@ -66,8 +66,7 @@ func TestAggregate(t *testing.T) {
 
 	folderCfg := defaultFolderCfg.Copy()
 	folderCfg.ID = "Aggregate"
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
+	ctx := t.Context()
 	a := newAggregator(ctx, folderCfg)
 
 	// checks whether maxFilesPerDir events in one dir are kept as is
@@ -140,7 +139,7 @@ func TestAggregate(t *testing.T) {
 		dirs[i] = "dir" + strconv.Itoa(i)
 	}
 	for _, dir := range dirs {
-		for i := 0; i < filesPerDir; i++ {
+		for i := range filesPerDir {
 			a.newEvent(fs.Event{
 				Name: filepath.Join(dir, strconv.Itoa(i)),
 				Type: fs.NonRemove,
@@ -163,7 +162,7 @@ func TestInProgress(t *testing.T) {
 		sleepMs(100)
 		c <- fs.Event{Name: "inprogress", Type: fs.NonRemove}
 		sleepMs(1000)
-		evLogger.Log(events.ItemFinished, map[string]interface{}{
+		evLogger.Log(events.ItemFinished, map[string]any{
 			"item": "inprogress",
 		})
 		sleepMs(100)
@@ -197,7 +196,7 @@ func TestDelay(t *testing.T) {
 		c <- fs.Event{Name: both, Type: fs.NonRemove}
 		c <- fs.Event{Name: both, Type: fs.Remove}
 		c <- fs.Event{Name: del, Type: fs.Remove}
-		for i := 0; i < 9; i++ {
+		for range 9 {
 			<-timer.C
 			timer.Reset(delay)
 			c <- fs.Event{Name: delayed, Type: fs.NonRemove}