diff --git a/libnetutils/packet.c b/libnetutils/packet.c
index be4e0db..3cdefb0 100644
--- a/libnetutils/packet.c
+++ b/libnetutils/packet.c
@@ -230,6 +230,8 @@
     packet.udp.check = 0;
     sum = finish_sum(checksum(&packet, nread, 0));
     packet.udp.check = temp;
+    if (!sum)
+        sum = finish_sum(sum);
     if (temp != sum) {
         ALOGW("UDP header checksum failure (0x%x should be 0x%x)", sum, temp);
         return -1;