diff --git a/src/quickfix.c b/src/quickfix.c
index 50da45fa67415a6140313ef98f5de1ad0bc3032b..56e8cb53f444a374e5aea5f7dc65232f8e61585b 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -4386,6 +4386,9 @@ qf_update_buffer(qf_info_T *qi, qfline_T *old_last)
     {
 	linenr_T	old_line_count = buf->b_ml.ml_line_count;
 
+	//autocommands may cause trouble  
+	incr_quickfix_busy();
+
 	if (old_last == NULL)
 	    // set curwin/curbuf to buf and save a few things
 	    aucmd_prepbuf(&aco, buf);
@@ -4407,6 +4410,10 @@ qf_update_buffer(qf_info_T *qi, qfline_T *old_last)
 	// when the added lines are not visible.
 	if ((win = qf_find_win(qi)) != NULL && old_line_count < win->w_botline)
 	    redraw_buf_later(buf, NOT_VALID);
+
+	// always called after incr_quickfix_busy()
+	decr_quickfix_busy();
+
     }
 }
 
diff --git a/src/testdir/test_quickfix.vim b/src/testdir/test_quickfix.vim
index f3f391cf658771c6cafd2afb4150aa10971a3c8e..8ccab24cbf405d06613294c096d6ab822b9cdf14 100644
--- a/src/testdir/test_quickfix.vim
+++ b/src/testdir/test_quickfix.vim
@@ -3389,6 +3389,23 @@ func Test_lbuffer_crash()
   augroup END
 endfunc
 
+func Test_filetype_autocmd()
+  " this changes the location list while it is in use to fill a buffer
+  lexpr ''
+  lopen
+  augroup FT_loclist
+    au FileType * call setloclist(0, [], 'f')
+  augroup END
+  silent! lolder
+  lexpr ''
+
+  augroup FT_loclist
+    au! FileType
+  augroup END
+endfunc
+
+
+
 " The following test used to crash vim
 func Test_lexpr_crash()
   augroup QF_Test