diff --git a/src/testdir/test_packadd.vim b/src/testdir/test_packadd.vim
index 89b7817..b44494a 100644
--- a/src/testdir/test_packadd.vim
+++ b/src/testdir/test_packadd.vim
@@ -21,6 +21,13 @@
   call mkdir(s:plugdir . '/plugin/also', 'p')
   call mkdir(s:plugdir . '/ftdetect', 'p')
   call mkdir(s:plugdir . '/after', 'p')
+
+  " This used to crash Vim
+  let &rtp = 'nosuchdir,' . s:plugdir . '/after'
+  packadd mytest
+  " plugdir should be inserted before plugdir/after
+  call assert_match('^nosuchdir,' . s:plugdir . ',', &rtp)
+
   set rtp&
   let rtp = &rtp
   filetype on