diff --git a/include/haproxy/mux_quic.h b/include/haproxy/mux_quic.h
index 6ba947785..232dfe7d2 100644
--- a/include/haproxy/mux_quic.h
+++ b/include/haproxy/mux_quic.h
@@ -109,14 +109,16 @@ static inline void qcs_wait_http_req(struct qcs *qcs)
 {
 	struct qcc *qcc = qcs->qcc;
 
-	/* A stream cannot be registered several times. */
-	BUG_ON_HOT(tick_isset(qcs->start));
-	qcs->start = now_ms;
+	if (!conn_is_back(qcc->conn)) {
+		/* A stream cannot be registered several times. */
+		BUG_ON_HOT(tick_isset(qcs->start));
+		qcs->start = now_ms;
 
-	/* qcc.opening_list size is limited by flow-control so no custom
-	 * restriction is needed here.
-	 */
-	LIST_APPEND(&qcc->opening_list, &qcs->el_opening);
+		/* qcc.opening_list size is limited by flow-control so no
+		 * custom restriction is needed here.
+		 */
+		LIST_APPEND(&qcc->opening_list, &qcs->el_opening);
+	}
 }
 
 void qcc_show_quic(struct qcc *qcc);
diff --git a/src/mux_quic.c b/src/mux_quic.c
index 5300ca5f6..ac798e475 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -259,6 +259,12 @@ static forceinline void qcc_reset_idle_start(struct qcc *qcc)
 	qcc->idle_start = now_ms;
 }
 
+/* Return true if the mux timeout should be armed. */
+static inline int qcc_may_expire(struct qcc *qcc)
+{
+	return !qcc->nb_sc;
+}
+
 /* Decrement <qcc> sc. */
 static forceinline void qcc_rm_sc(struct qcc *qcc)
 {
@@ -268,7 +274,7 @@ static forceinline void qcc_rm_sc(struct qcc *qcc)
 	/* Reset qcc idle start for http-keep-alive timeout. Timeout will be
 	 * refreshed after this on stream detach.
 	 */
-	if (!qcc->nb_sc && !qcc->nb_hreq)
+	if (!conn_is_back(qcc->conn) && qcc_may_expire(qcc) && !qcc->nb_hreq)
 		qcc_reset_idle_start(qcc);
 }
 
@@ -281,7 +287,7 @@ static forceinline void qcc_rm_hreq(struct qcc *qcc)
 	/* Reset qcc idle start for http-keep-alive timeout. Timeout will be
 	 * refreshed after this on I/O handler.
 	 */
-	if (!qcc->nb_sc && !qcc->nb_hreq)
+	if (!conn_is_back(qcc->conn) && qcc_may_expire(qcc) && !qcc->nb_hreq)
 		qcc_reset_idle_start(qcc);
 }
 
@@ -308,12 +314,6 @@ static inline int qcc_is_dead(const struct qcc *qcc)
 	return 0;
 }
 
-/* Return true if the mux timeout should be armed. */
-static inline int qcc_may_expire(struct qcc *qcc)
-{
-	return !qcc->nb_sc;
-}
-
 /* Refresh the timeout on <qcc> if needed depending on its state. */
 static void qcc_refresh_timeout(struct qcc *qcc)
 {