diff --git a/src/testdir/test_ins_complete.vim b/src/testdir/test_ins_complete.vim
index 2be6d06..7bebc5d 100644
--- a/src/testdir/test_ins_complete.vim
+++ b/src/testdir/test_ins_complete.vim
@@ -2108,6 +2108,13 @@
   exe "normal 2Go\<C-X>\<C-L>\<Esc>"
   call assert_equal(longLine, getline(3))
 
+  " check that the too long text is NUL terminated
+  %del
+  norm o
+  norm 1987ax
+  exec "norm ox\<C-X>\<C-L>"
+  call assert_equal(repeat('x', 1987), getline(3))
+
   bwipe!
   set noic noinfercase
 endfunc