diff --git a/include/haproxy/stconn.h b/include/haproxy/stconn.h
index 9c7be5032..ff0de4354 100644
--- a/include/haproxy/stconn.h
+++ b/include/haproxy/stconn.h
@@ -51,6 +51,10 @@ int sc_reset_endp(struct stconn *sc);
 
 struct appctx *sc_applet_create(struct stconn *sc, struct applet *app);
 
+void sc_conn_prepare_endp_upgrade(struct stconn *sc);
+void sc_conn_abort_endp_upgrade(struct stconn *sc);
+void sc_conn_commit_endp_upgrade(struct stconn *sc);
+
 /* The se_fl_*() set of functions manipulate the stream endpoint flags from
  * the stream endpoint itself. The sc_ep_*() set of functions manipulate the
  * stream endpoint flags from the the stream connector (ex. stconn).
diff --git a/src/stconn.c b/src/stconn.c
index 5d4ed3ed4..02a8dc452 100644
--- a/src/stconn.c
+++ b/src/stconn.c
@@ -1943,3 +1943,35 @@ static int sc_applet_process(struct stconn *sc)
 		appctx_wakeup(__sc_appctx(sc));
 	return 0;
 }
+
+
+/* Prepares an endpoint upgrade. We don't now at this stage if the upgrade will
+ * succeed or not and if the stconn will be reused by the new endpoint. Thus,
+ * for now, only pretend the stconn is detached.
+ */
+void sc_conn_prepare_endp_upgrade(struct stconn *sc)
+{
+	BUG_ON(!sc_conn(sc) || !sc->app);
+	sc_ep_clr(sc, SE_FL_T_MUX);
+	sc_ep_set(sc, SE_FL_DETACHED);
+}
+
+/* Endpoint upgrade failed. Retore the stconn state. */
+void sc_conn_abort_endp_upgrade(struct stconn *sc)
+{
+	sc_ep_set(sc, SE_FL_T_MUX);
+	sc_ep_clr(sc, SE_FL_DETACHED);
+}
+
+/* Commit the endpoint upgrade. If stconn is attached, it means the new endpoint
+ * use it. So we do nothing. Otherwise, the stconn will be destroy with the
+ * overlying stream. So, it means we must commit the detach.
+*/
+void sc_conn_commit_endp_upgrade(struct stconn *sc)
+{
+	if (!sc_ep_test(sc, SE_FL_DETACHED))
+		return;
+	sc_detach_endp(&sc);
+	/* Because it was already set as detached, the sedesc must be preserved */
+	BUG_ON(!sc->sedesc);
+}
diff --git a/src/stream.c b/src/stream.c
index f3f776db6..2f698482f 100644
--- a/src/stream.c
+++ b/src/stream.c
@@ -1485,10 +1485,15 @@ int stream_set_http_mode(struct stream *s, const struct mux_proto_list *mux_prot
 
 		if (conn->mux->flags & MX_FL_NO_UPG)
 			return 0;
+
+		sc_conn_prepare_endp_upgrade(sc);
 		if (conn_upgrade_mux_fe(conn, sc, &s->req.buf,
 					(mux_proto ? mux_proto->token : ist("")),
-					PROTO_MODE_HTTP)  == -1)
+					PROTO_MODE_HTTP)  == -1) {
+			sc_conn_abort_endp_upgrade(sc);
 			return 0;
+		}
+		sc_conn_commit_endp_upgrade(sc);
 
 		s->req.flags &= ~(CF_READ_PARTIAL|CF_AUTO_CONNECT);
 		s->req.total = 0;