diff --git a/src/hev-socks5-session.c b/src/hev-socks5-session.c
index fb12a31..b8660ce 100644
--- a/src/hev-socks5-session.c
+++ b/src/hev-socks5-session.c
@@ -836,7 +836,7 @@ socks5_do_fwd_udp (HevSocks5Session *self)
         if (res_b >= 0)
             res_b = udp_fwd_b (self);
 
-        if (res_f < 0 && res_b < 0)
+        if (res_f < 0 || res_b < 0)
             break;
         else if (res_f > 0 || res_b > 0)
             type = HEV_TASK_YIELD;