diff --git a/src/evalvars.c b/src/evalvars.c
index 79c7a9c..cd50ba7 100644
--- a/src/evalvars.c
+++ b/src/evalvars.c
@@ -789,8 +789,11 @@
 	{
 	    if (vim9script)
 	    {
-		// Vim9 declaration ":var name: type"
-		arg = vim9_declare_scriptvar(eap, arg);
+		if (!ends_excmd2(eap->cmd, skipwhite(argend)))
+		    semsg(_(e_trailing_arg), argend);
+		else
+		    // Vim9 declaration ":var name: type"
+		    arg = vim9_declare_scriptvar(eap, arg);
 	    }
 	    else
 	    {
diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index f71226e..b9851a7 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -1290,6 +1290,8 @@
     other = 1234
     g:other_var = other
 
+    var xyz: string  # comment
+
     # type is inferred
     var s:dict = {['a']: 222}
     def GetDictVal(key: any)
@@ -1365,7 +1367,7 @@
     vim9script
     var 9var: string
   END
-  CheckScriptFailure(lines, 'E475:')
+  CheckScriptFailure(lines, 'E488:')
 
   CheckDefFailure(['var foo.bar = 2'], 'E1087:')
   CheckDefFailure(['var foo[3] = 2'], 'E1087:')
@@ -1617,6 +1619,11 @@
       echo x
   END
   CheckScriptFailureList(lines, ['E1154:', 'E121:'])
+
+  lines =<< trim END
+      var x: string  'string'
+  END
+  CheckDefAndScriptFailure(lines, 'E488:')
 enddef
 
 
diff --git a/src/version.c b/src/version.c
index 373ec74..f172437 100644
--- a/src/version.c
+++ b/src/version.c
@@ -751,6 +751,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    2660,
+/**/
     2659,
 /**/
     2658,