diff --git a/src/testdir/test_vim9_assign.vim b/src/testdir/test_vim9_assign.vim
index dffec4f..6b6311a 100644
--- a/src/testdir/test_vim9_assign.vim
+++ b/src/testdir/test_vim9_assign.vim
@@ -1722,6 +1722,8 @@
   END
   CheckScriptFailure(lines, 'E1069:')
 
+  CheckDefAndScriptFailure(['var n:number = 42'], 'E1069:')
+
   lines =<< trim END
     vim9script
     var name: asdf