diff --git a/src/testdir/test_modeline.vim b/src/testdir/test_modeline.vim
new file mode 100644
index 0000000..6e49577
--- /dev/null
+++ b/src/testdir/test_modeline.vim
@@ -0,0 +1,8 @@
+" Tests for parsing the modeline.
+
+func Test_invalid()
+  " This was reading before allocated memory.
+  call writefile(['vi:0', 'nothing'], 'Xmodeline')
+  call assert_fails('split Xmodeline', 'E518:')
+  bwipe!
+endfunc