diff --git a/src/quickfix.c b/src/quickfix.c
index 0da8ea2..35a66dc 100644
--- a/src/quickfix.c
+++ b/src/quickfix.c
@@ -7963,9 +7963,10 @@
     {
 	apply_autocmds(EVENT_QUICKFIXCMDPOST, au_name,
 					       curbuf->b_fname, TRUE, curbuf);
-	if (!new_qi && IS_LL_STACK(qi) && qf_find_buf(qi) == NULL)
+	// When adding a location list to an existing location list stack,
+	// if the autocmd made the stack invalid, then just return.
+	if (!new_qi && IS_LL_STACK(qi) && qf_find_win_with_loclist(qi) == NULL)
 	{
-	    // autocommands made "qi" invalid
 	    decr_quickfix_busy();
 	    return;
 	}