diff --git a/include/haproxy/protocol-t.h b/include/haproxy/protocol-t.h
index b0765cf87..e49a239ce 100644
--- a/include/haproxy/protocol-t.h
+++ b/include/haproxy/protocol-t.h
@@ -113,6 +113,7 @@ struct protocol {
 	void (*ignore_events)(struct connection *conn, int event_type);  /* unsubscribe from socket events */
 	int (*get_src)(struct connection *conn, struct sockaddr *, socklen_t); /* retrieve connection's source address; -1=fail */
 	int (*get_dst)(struct connection *conn, struct sockaddr *, socklen_t); /* retrieve connection's dest address; -1=fail */
+	int (*set_affinity)(struct connection *conn, int new_tid);
 
 	/* functions acting on the receiver */
 	int (*rx_suspend)(struct receiver *rx);         /* temporarily suspend this receiver for a soft restart */
diff --git a/src/listener.c b/src/listener.c
index 5fe714ba5..07c7f92ea 100644
--- a/src/listener.c
+++ b/src/listener.c
@@ -1194,6 +1194,13 @@ void listener_accept(struct listener *l)
 				t1 += (t2 << 16);
 			} while (unlikely(!_HA_ATOMIC_CAS(&l->thr_idx, &t0, t1)));
 
+			if (l->rx.proto && l->rx.proto->set_affinity) {
+				if (l->rx.proto->set_affinity(cli_conn, base + t)) {
+					/* Failed migration, stay on the same thread. */
+					goto local_accept;
+				}
+			}
+
 			/* We successfully selected the best thread "t" for this
 			 * connection. We use deferred accepts even if it's the
 			 * local thread because tests show that it's the best