diff --git a/src/testdir/test_vim9_func.vim b/src/testdir/test_vim9_func.vim
index 53206df..99b2a11 100644
--- a/src/testdir/test_vim9_func.vim
+++ b/src/testdir/test_vim9_func.vim
@@ -954,6 +954,14 @@
   assert_equal(6, res)
 enddef
 
+def Wrong_dict_key_type(items: list<number>): list<number>
+  return filter(items, {_, val -> get({val: 1}, 'x')})
+enddef
+
+def Test_wrong_dict_key_type()
+  assert_fails('Wrong_dict_key_type([1, 2, 3])', 'E1029:')
+enddef
+
 def Line_continuation_in_def(dir: string = ''): string
     let path: string = empty(dir)
             \ ? 'empty'