diff --git a/include/net/netfilter/nf_conntrack.h b/include/net/netfilter/nf_conntrack.h
index dd78bea..b6083c3 100644
--- a/include/net/netfilter/nf_conntrack.h
+++ b/include/net/netfilter/nf_conntrack.h
@@ -284,6 +284,14 @@
 	return skb->dev && skb->skb_iif && skb->dev->flags & IFF_LOOPBACK;
 }
 
+/* jiffies until ct expires, 0 if already expired */
+static inline unsigned long nf_ct_expires(const struct nf_conn *ct)
+{
+	long timeout = (long)ct->timeout.expires - (long)jiffies;
+
+	return timeout > 0 ? timeout : 0;
+}
+
 struct kernel_param;
 
 int nf_conntrack_set_hashsize(const char *val, struct kernel_param *kp);