diff --git a/include/uapi/linux/mptcp.h b/include/uapi/linux/mptcp.h
index ee9c49f949a2..00d622121673 100644
--- a/include/uapi/linux/mptcp.h
+++ b/include/uapi/linux/mptcp.h
@@ -81,6 +81,8 @@ enum {
 
 #define MPTCP_PM_ADDR_ATTR_MAX (__MPTCP_PM_ADDR_ATTR_MAX - 1)
 
+#define MPTCP_PM_EV_FLAG_DENY_JOIN_ID0		_BITUL(0)
+
 #define MPTCP_PM_ADDR_FLAG_SIGNAL			(1 << 0)
 #define MPTCP_PM_ADDR_FLAG_SUBFLOW			(1 << 1)
 #define MPTCP_PM_ADDR_FLAG_BACKUP			(1 << 2)
@@ -132,13 +134,13 @@ struct mptcp_info {
 
 /*
  * MPTCP_EVENT_CREATED: token, family, saddr4 | saddr6, daddr4 | daddr6,
- *                      sport, dport
+ *                      sport, dport, server-side, [flags]
  * A new MPTCP connection has been created. It is the good time to allocate
  * memory and send ADD_ADDR if needed. Depending on the traffic-patterns
  * it can take a long time until the MPTCP_EVENT_ESTABLISHED is sent.
  *
  * MPTCP_EVENT_ESTABLISHED: token, family, saddr4 | saddr6, daddr4 | daddr6,
- *			    sport, dport
+ *			    sport, dport, server-side, [flags]
  * A MPTCP connection is established (can start new subflows).
  *
  * MPTCP_EVENT_CLOSED: token
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index e8042014bd5f..de24989b05a6 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -2252,6 +2252,7 @@ static int mptcp_event_created(struct sk_buff *skb,
 			       const struct sock *ssk)
 {
 	int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
+	u16 flags = 0;
 
 	if (err)
 		return err;
@@ -2259,6 +2260,12 @@ static int mptcp_event_created(struct sk_buff *skb,
 	if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
 		return -EMSGSIZE;
 
+	if (READ_ONCE(msk->pm.remote_deny_join_id0))
+		flags |= MPTCP_PM_EV_FLAG_DENY_JOIN_ID0;
+
+	if (flags && nla_put_u16(skb, MPTCP_ATTR_FLAGS, flags))
+		return -EMSGSIZE;
+
 	return mptcp_event_add_subflow(skb, ssk);
 }