diff --git a/src/testdir/test_edit.vim b/src/testdir/test_edit.vim
index bb3af27..f857516 100644
--- a/src/testdir/test_edit.vim
+++ b/src/testdir/test_edit.vim
@@ -215,14 +215,16 @@
 
 func! Test_edit_08()
   " reset insertmode from i_ctrl-r_=
+  let g:bufnr = bufnr('%')
   new
   call setline(1, ['abc'])
   call cursor(1, 4)
-  call feedkeys(":set im\<cr>ZZZ\<c-r>=setbufvar(1,'&im', 0)\<cr>",'tnix')
+  call feedkeys(":set im\<cr>ZZZ\<c-r>=setbufvar(g:bufnr,'&im', 0)\<cr>",'tnix')
   call assert_equal(['abZZZc'], getline(1,'$'))
   call assert_equal([0, 1, 1, 0], getpos('.'))
   call assert_false(0, '&im')
   bw!
+  unlet g:bufnr
 endfunc
 
 func! Test_edit_09()