diff --git a/Documentation/netlink/specs/mptcp_pm.yaml b/Documentation/netlink/specs/mptcp_pm.yaml
index fc47a2931014..ba30a40b9dbf 100644
--- a/Documentation/netlink/specs/mptcp_pm.yaml
+++ b/Documentation/netlink/specs/mptcp_pm.yaml
@@ -266,6 +266,7 @@ attribute-sets:
       -
         name: server-side
         type: u8
+        doc: "Deprecated: use 'flags'"
 
 operations:
   list:
diff --git a/net/mptcp/pm_netlink.c b/net/mptcp/pm_netlink.c
index aa0c73faaa6a..d5b383870f79 100644
--- a/net/mptcp/pm_netlink.c
+++ b/net/mptcp/pm_netlink.c
@@ -416,7 +416,7 @@ static int mptcp_event_created(struct sk_buff *skb,
 	if (READ_ONCE(msk->pm.server_side)) {
 		flags |= MPTCP_PM_EV_FLAG_SERVER_SIDE;
 
-		/* only set when it is the server side */
+		/* Deprecated, and only set when it is the server side */
 		if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, 1))
 			return -EMSGSIZE;
 	}