diff --git a/src/testdir/test_bufline.vim b/src/testdir/test_bufline.vim
index 6d62e51..183a186 100644
--- a/src/testdir/test_bufline.vim
+++ b/src/testdir/test_bufline.vim
@@ -132,7 +132,7 @@
   call assert_equal(0, deletebufline(b, 2, 8))
   call assert_equal(['aaa'], getbufline(b, 1, 2))
   exe "bd!" b
-  call assert_equal(1, deletebufline(b, 1))
+  call assert_equal(1, b->deletebufline(1))
 
   call assert_equal(1, deletebufline(-1, 1))