diff --git a/src/testdir/test_unlet.vim b/src/testdir/test_unlet.vim
index dad0953..6be9633 100644
--- a/src/testdir/test_unlet.vim
+++ b/src/testdir/test_unlet.vim
@@ -27,6 +27,7 @@
   call assert_fails("unlet l['k'", 'E111:')
   let d = {'k' : 1}
   call assert_fails("unlet d.k2", 'E716:')
+  call assert_fails("unlet {a};", 'E488:')
 endfunc
 
 func Test_unlet_env()