diff --git a/src/testdir/test_modeline.vim b/src/testdir/test_modeline.vim
index 0a7240b..bb5bc6b 100644
--- a/src/testdir/test_modeline.vim
+++ b/src/testdir/test_modeline.vim
@@ -208,6 +208,7 @@
   call s:modeline_fails('equalprg', 'equalprg=Something()', 'E520:')
   call s:modeline_fails('errorfile', 'errorfile=Something()', 'E520:')
   call s:modeline_fails('exrc', 'exrc=Something()', 'E520:')
+  call s:modeline_fails('findexpr', 'findexpr=Something()', 'E520:')
   call s:modeline_fails('formatprg', 'formatprg=Something()', 'E520:')
   call s:modeline_fails('fsync', 'fsync=Something()', 'E520:')
   call s:modeline_fails('grepprg', 'grepprg=Something()', 'E520:')