diff --git a/net/netfilter/nf_conntrack_proto_gre.c b/net/netfilter/nf_conntrack_proto_gre.c
index cf616e55ca41..d69facdd9a7a 100644
--- a/net/netfilter/nf_conntrack_proto_gre.c
+++ b/net/netfilter/nf_conntrack_proto_gre.c
@@ -241,8 +241,8 @@ static int gre_packet(struct nf_conn *ct,
 		nf_ct_refresh_acct(ct, ctinfo, skb,
 				   ct->proto.gre.stream_timeout);
 		/* Also, more likely to be important, and not a probe. */
-		set_bit(IPS_ASSURED_BIT, &ct->status);
-		nf_conntrack_event_cache(IPCT_ASSURED, ct);
+		if (!test_and_set_bit(IPS_ASSURED_BIT, &ct->status))
+			nf_conntrack_event_cache(IPCT_ASSURED, ct);
 	} else
 		nf_ct_refresh_acct(ct, ctinfo, skb,
 				   ct->proto.gre.timeout);