diff --git a/window-manipulator/README.md b/window-manipulator/README.md
index 46d37cf..0a74599 100644
--- a/window-manipulator/README.md
+++ b/window-manipulator/README.md
@@ -2,9 +2,7 @@
 
 ## What it does
 
-This extension includes a browser action with a popup specified as "window.html".
-
-The popup lets the user perform various simple operations using the windows API.
+This extension create a sidebar, specified as "window.html", that lets the user perform various simple operations using the windows API.
 
 # What it shows
 
diff --git a/window-manipulator/manifest.json b/window-manipulator/manifest.json
index 5963b9b..e392966 100644
--- a/window-manipulator/manifest.json
+++ b/window-manipulator/manifest.json
@@ -1,8 +1,8 @@
 {
-  "browser_action": {
+  "sidebar_action": {
     "browser_style": true,
     "default_title": "Window manipulator",
-    "default_popup": "window.html",
+    "default_panel": "window.html",
     "default_icon": {
       "19": "icons/window19.png",
       "38": "icons/window38.png"