diff --git a/src/testdir/test_assign.vim b/src/testdir/test_assign.vim
index 4a4c644..efc9d08 100644
--- a/src/testdir/test_assign.vim
+++ b/src/testdir/test_assign.vim
@@ -15,7 +15,7 @@
   call assert_match('t_te.*^[[yes;', execute("set termcap"))
   let &t_te = old_t_te
 
-  if !has('gui_running')
+  if exists("+t_k1")
     " Key code
     let old_t_k1 = &t_k1
     let &t_k1 = "that"