diff --git a/bpf_progs/offload.c b/bpf_progs/offload.c
index 8645dd7..c752779 100644
--- a/bpf_progs/offload.c
+++ b/bpf_progs/offload.c
@@ -194,6 +194,7 @@
 
     TetherUpstream6Key ku = {
             .iif = skb->ifindex,
+            .src64 = 0,
     };
     if (is_ethernet) __builtin_memcpy(downstream ? kd.dstMac : ku.dstMac, eth->h_dest, ETH_ALEN);