diff --git a/src/testdir/test_spell.vim b/src/testdir/test_spell.vim
index c2de5ed..4beff9a 100644
--- a/src/testdir/test_spell.vim
+++ b/src/testdir/test_spell.vim
@@ -112,6 +112,7 @@
 
   set spelllang=
   call assert_fails("call spellbadword('maxch')", 'E756:')
+  call assert_fails("spelldump", 'E756:')
 
   call delete('Xwords.spl')
   call delete('Xwords')