diff --git a/channels/chan_sip.c b/channels/chan_sip.c
index a9f29721e9..0f1edc1db9 100644
--- a/channels/chan_sip.c
+++ b/channels/chan_sip.c
@@ -9396,8 +9396,6 @@ 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 (!authpeer)	/* If we are looking for a peer, don't check the user objects (or realtime) */
 		user = find_user(of, 1);