diff --git a/src/testdir/test_help.vim b/src/testdir/test_help.vim
index c550ff0..5dd937a 100644
--- a/src/testdir/test_help.vim
+++ b/src/testdir/test_help.vim
@@ -20,6 +20,12 @@
   bwipe!
 endfunc
 
+func Test_help_expr()
+  help expr-!~?
+  call assert_equal('eval.txt', expand('%:t'))
+  close
+endfunc
+
 func Test_help_keyword()
   new
   set keywordprg=:help