diff --git a/src/testdir/test_vim9_expr.vim b/src/testdir/test_vim9_expr.vim
index 79a4ea3..f0e15c3 100644
--- a/src/testdir/test_vim9_expr.vim
+++ b/src/testdir/test_vim9_expr.vim
@@ -2478,6 +2478,13 @@
   else
     CheckDefAndScriptFailure(lines, 'E117:', 0)
   endif
+
+  lines =<< trim END
+      vim9script
+      var x = 99
+      assert_equal({x: 99}, s:)
+  END
+  CheckScriptSuccess(lines)
 enddef
 
 def Test_expr7_call_2bool()