diff --git a/src/mux_pt.c b/src/mux_pt.c
index 72c997d41..c5eb8c60b 100644
--- a/src/mux_pt.c
+++ b/src/mux_pt.c
@@ -415,7 +415,7 @@ static void mux_pt_detach(struct conn_stream *cs)
 	TRACE_ENTER(PT_EV_STRM_END, conn, cs);
 
 	/* Subscribe, to know if we got disconnected */
-	if (conn->owner != NULL &&
+	if (!conn_is_back(conn) && conn->owner != NULL &&
 	    !(conn->flags & (CO_FL_ERROR | CO_FL_SOCK_RD_SH | CO_FL_SOCK_WR_SH))) {
 		ctx->cs = NULL;
 		conn->xprt->subscribe(conn, conn->xprt_ctx, SUB_RETRY_RECV, &ctx->wait_event);