diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index f6fcf95e5..cf6a4e509 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -592,10 +592,10 @@ enum qc_mux_state {
 #define QUIC_FL_CONN_POST_HANDSHAKE_FRAMES_BUILT (1U << 2)
 #define QUIC_FL_CONN_LISTENER                    (1U << 3)
 #define QUIC_FL_CONN_ACCEPT_REGISTERED           (1U << 4)
-/* gap here */
+#define QUIC_FL_CONN_RETRANS_LOST_DATA           (1U << 5) /* retransmission in progress for lost data */
 #define QUIC_FL_CONN_IDLE_TIMER_RESTARTED_AFTER_READ (1U << 6)
 #define QUIC_FL_CONN_RETRANS_NEEDED              (1U << 7)
-#define QUIC_FL_CONN_RETRANS_OLD_DATA            (1U << 8)
+#define QUIC_FL_CONN_RETRANS_OLD_DATA            (1U << 8) /* retransmission in progress for probing with already sent data */
 #define QUIC_FL_CONN_TLS_ALERT                   (1U << 9)
 /* gap here */
 #define QUIC_FL_CONN_HALF_OPEN_CNT_DECREMENTED   (1U << 11) /* The half-open connection counter was decremented */
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 55001e8f4..b9f274256 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -3884,7 +3884,9 @@ static int qc_qel_may_rm_hp(struct quic_conn *qc, struct quic_enc_level *qel)
 
 /* Try to send application frames from list <frms> on connection <qc>.
  *
- * Use qc_send_app_probing wrapper when probing with old data.
+ * For retransmission you must use wrapper depending on the sending condition :
+ * - use qc_send_app_retransmit to send data detected as lost
+ * - use qc_send_app_probing when probing with already sent data
  *
  * Returns 1 on success. Some data might not have been sent due to congestion,
  * in this case they are left in <frms> input list. The caller may subscribe on
@@ -3940,6 +3942,27 @@ int qc_send_app_pkts(struct quic_conn *qc, struct list *frms)
 	goto leave;
 }
 
+/* Try to send application frames from list <frms> on connection <qc>. Use this
+ * function when retransmitting lost frames.
+ *
+ * Returns the result from qc_send_app_pkts function.
+ */
+static forceinline int qc_send_app_retransmit(struct quic_conn *qc,
+                                              struct list *frms)
+{
+	int ret;
+
+	TRACE_ENTER(QUIC_EV_CONN_TXPKT, qc);
+
+	TRACE_STATE("preparing lost data (retransmission)", QUIC_EV_CONN_TXPKT, qc);
+	qc->flags |= QUIC_FL_CONN_RETRANS_LOST_DATA;
+	ret = qc_send_app_pkts(qc, frms);
+	qc->flags &= ~QUIC_FL_CONN_RETRANS_LOST_DATA;
+
+	TRACE_LEAVE(QUIC_EV_CONN_TXPKT, qc);
+	return ret;
+}
+
 /* Try to send application frames from list <frms> on connection <qc>. Use this
  * function when probing is required.
  *
@@ -4131,8 +4154,8 @@ static struct task *quic_conn_app_io_cb(struct task *t, void *context, unsigned
 	}
 
 	/* XXX TODO: how to limit the list frames to send */
-	if (!qc_send_app_pkts(qc, &qel->pktns->tx.frms)) {
-		TRACE_DEVEL("qc_send_app_pkts() failed", QUIC_EV_CONN_IO_CB, qc);
+	if (!qc_send_app_retransmit(qc, &qel->pktns->tx.frms)) {
+		TRACE_DEVEL("qc_send_app_retransmit() failed", QUIC_EV_CONN_IO_CB, qc);
 		goto out;
 	}
 
@@ -6462,12 +6485,9 @@ static inline int qc_build_frms(struct list *outlist, struct list *inlist,
 				LIST_DELETE(&cf->list);
 				LIST_APPEND(outlist, &cf->list);
 
-				/* The MUX stream might be released at this
-				 * stage. This can most notably happen on
-				 * retransmission.
-				 */
-				if (qc->mux_state == QC_MUX_READY &&
-				    !cf->stream.stream->release) {
+				/* Do not notify MUX on retransmission. */
+				if (!(qc->flags & (QUIC_FL_CONN_RETRANS_LOST_DATA|QUIC_FL_CONN_RETRANS_OLD_DATA))) {
+					BUG_ON(qc->mux_state != QC_MUX_READY); /* MUX must be the caller if not on retransmission. */
 					qcc_streams_sent_done(cf->stream.stream->ctx,
 					                      cf->stream.len,
 					                      cf->stream.offset.key);
@@ -6505,12 +6525,9 @@ static inline int qc_build_frms(struct list *outlist, struct list *inlist,
 				cf->stream.offset.key += dlen;
 				cf->stream.data = (unsigned char *)b_peek(&cf_buf, dlen);
 
-				/* The MUX stream might be released at this
-				 * stage. This can most notably happen on
-				 * retransmission.
-				 */
-				if (qc->mux_state == QC_MUX_READY &&
-				    !cf->stream.stream->release) {
+				/* Do not notify MUX on retransmission. */
+				if (!(qc->flags & (QUIC_FL_CONN_RETRANS_LOST_DATA|QUIC_FL_CONN_RETRANS_OLD_DATA))) {
+					BUG_ON(qc->mux_state != QC_MUX_READY); /* MUX must be the caller if not on retransmission. */
 					qcc_streams_sent_done(new_cf->stream.stream->ctx,
 					                      new_cf->stream.len,
 					                      new_cf->stream.offset.key);