diff --git a/tests/test.cmp b/tests/test.cmp
index 535502e4..044dc10e 100644
--- a/tests/test.cmp
+++ b/tests/test.cmp
@@ -5096,6 +5096,17 @@ REM This should be diganosed as implicitly being MSG-type
 This should be diganosed as implicitly being MSG-type
 
 
+# Check that user-defined functions with too many arguments are
+# correctly diagnosed.
+
+# This should be OK
+FSET f(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61, a62, a63) 3
+
+# This should give an error
+FSET f(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61, a62, a63, a64) 3
+../tests/test.rem(1008): Too many arguments
+
+
 # Don't want Remind to queue reminders
 EXIT
 
diff --git a/tests/test.rem b/tests/test.rem
index 6189d432..bd50586a 100644
--- a/tests/test.rem
+++ b/tests/test.rem
@@ -998,6 +998,16 @@ msg [shellescape("😆")]
 This should be diagnosed as implicitly being REM
 REM This should be diganosed as implicitly being MSG-type
 
+# Check that user-defined functions with too many arguments are
+# correctly diagnosed.
+
+# This should be OK
+FSET f(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61, a62, a63) 3
+
+# This should give an error
+FSET f(a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20, a21, a22, a23, a24, a25, a26, a27, a28, a29, a30, a31, a32, a33, a34, a35, a36, a37, a38, a39, a40, a41, a42, a43, a44, a45, a46, a47, a48, a49, a50, a51, a52, a53, a54, a55, a56, a57, a58, a59, a60, a61, a62, a63, a64) 3
+
+
 # Don't want Remind to queue reminders
 EXIT