diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c
index e187bf0..a6abee0 100644
--- a/net/core/flow_dissector.c
+++ b/net/core/flow_dissector.c
@@ -159,8 +159,9 @@ void __skb_get_rxhash(struct sk_buff *skb)
 	struct flow_keys keys;
 	u32 hash;
 
-	if (!skb_flow_dissect(skb, &keys))
+	if (skb->rxhash || !skb_flow_dissect(skb, &keys)) {
 		return;
+	}
 
 	if (keys.ports)
 		skb->l4_rxhash = 1;