diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index a110252e46acb971a98fba16b0f0022eebdac874..f6dcfa571d376177ee379b7eecb8ab94f42e0f9c 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -11511,8 +11511,6 @@ static enum check_auth_result check_user_full(struct sip_pvt *p, struct sip_requ
 			ast_shrink_phone_number(tmp);
 		ast_string_field_set(p, cid_num, tmp);
 	}
-	if (ast_strlen_zero(of))
-		return AUTH_SUCCESSFUL;
 
 	if (global_match_auth_username) {
 		/*