diff --git a/src/mux_quic.c b/src/mux_quic.c
index f89d4502f784..2f550f758eef 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -37,6 +37,11 @@ static void qcs_free_ncbuf(struct qcs *qcs, struct ncbuf *ncbuf)
 	offer_buffers(NULL, 1);
 
 	*ncbuf = NCBUF_NULL;
+
+	/* Reset DEM_FULL as buffer is released. This ensures mux is not woken
+	 * up from rcv_buf stream callback when demux was previously blocked.
+	 */
+	qcs->flags &= ~QC_SF_DEM_FULL;
 }
 
 /* Free <qcs> instance. This function is reserved for internal usage : it must
@@ -2743,9 +2748,8 @@ static size_t qmux_strm_rcv_buf(struct stconn *sc, struct buffer *buf,
 
 	/* Restart demux if it was interrupted on full buffer. */
 	if (ret && qcs->flags & QC_SF_DEM_FULL) {
-		/* There must be data left for demux if it was interrupted on
-		 * full buffer. If this assumption is incorrect wakeup is not
-		 * necessary.
+		/* Ensure DEM_FULL is only set if there is available data to
+		 * ensure we never do unnecessary wakeup here.
 		 */
 		BUG_ON(!ncb_data(&qcs->rx.ncbuf, 0));