diff --git a/runtime/autoload/tutor.vim b/runtime/autoload/tutor.vim
index abf5c5e2c8..4da4213826 100644
--- a/runtime/autoload/tutor.vim
+++ b/runtime/autoload/tutor.vim
@@ -104,7 +104,7 @@ function! tutor#CheckLine(line)
     if exists('b:tutor_metadata') && has_key(b:tutor_metadata, 'expect')
         let bufn = bufnr('%')
         let ctext = getline(a:line)
-        let signs = sign_getplaced('.', {'lnum': a:line})[0].signs
+        let signs = sign_getplaced(bufn, {'lnum': a:line})[0].signs
         if !empty(signs)
             call sign_unplace('', {'id': signs[0].id})
         endif