diff --git a/include/haproxy/quic_stream.h b/include/haproxy/quic_stream.h
index 57f8c455f..44897287b 100644
--- a/include/haproxy/quic_stream.h
+++ b/include/haproxy/quic_stream.h
@@ -10,7 +10,7 @@ struct quic_conn;
 
 struct qc_stream_desc *qc_stream_desc_new(uint64_t id, enum qcs_type, void *ctx,
                                           struct quic_conn *qc);
-void qc_stream_desc_release(struct qc_stream_desc *stream);
+void qc_stream_desc_release(struct qc_stream_desc *stream, uint64_t final_size);
 int qc_stream_desc_ack(struct qc_stream_desc **stream, size_t offset, size_t len);
 void qc_stream_desc_free(struct qc_stream_desc *stream, int closing);
 
diff --git a/src/mux_quic.c b/src/mux_quic.c
index a6af629a8..55c395a09 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -68,7 +68,7 @@ static void qcs_free(struct qcs *qcs)
 		qcc->app_ops->detach(qcs);
 
 	/* Release qc_stream_desc buffer from quic-conn layer. */
-	qc_stream_desc_release(qcs->stream);
+	qc_stream_desc_release(qcs->stream, qcs->tx.sent_offset);
 
 	/* Free Rx/Tx buffers. */
 	qcs_free_ncbuf(qcs, &qcs->rx.ncbuf);
diff --git a/src/quic_stream.c b/src/quic_stream.c
index 727636b06..42452c2c0 100644
--- a/src/quic_stream.c
+++ b/src/quic_stream.c
@@ -85,8 +85,13 @@ struct qc_stream_desc *qc_stream_desc_new(uint64_t id, enum qcs_type type, void
 /* Mark the stream descriptor <stream> as released. It will be freed as soon as
  * all its buffered data are acknowledged. Does nothing if <stream> is already
  * NULL.
+ *
+ * <final_size> corresponds to the last offset sent for this stream. If there
+ * is unsent data present, they will be remove first to guarantee that buffer
+ * is freed after receiving all acknowledges.
  */
-void qc_stream_desc_release(struct qc_stream_desc *stream)
+void qc_stream_desc_release(struct qc_stream_desc *stream,
+                            uint64_t final_size)
 {
 	if (!stream)
 		return;
@@ -97,14 +102,31 @@ void qc_stream_desc_release(struct qc_stream_desc *stream)
 	stream->release = 1;
 	stream->ctx = NULL;
 
+	if (stream->buf) {
+		struct qc_stream_buf *stream_buf = stream->buf;
+		struct buffer *buf = &stream_buf->buf;
+		const uint64_t tail_offset =
+		  MAX(stream->buf_offset, stream->ack_offset) + b_data(buf);
+
+		/* final_size cannot be greater than all currently stored data. */
+		BUG_ON(final_size > tail_offset);
+
+		/* Remove unsent data from current buffer. */
+		if (final_size < tail_offset) {
+			b_sub(buf, tail_offset - final_size);
+			/* Remove buffer is all ACK already received. */
+			if (!b_data(buf))
+				qc_stream_buf_free(stream, &stream_buf);
+		}
+
+		/* A released stream does not use <stream.buf>. */
+		stream->buf = NULL;
+	}
+
 	if (LIST_ISEMPTY(&stream->buf_list)) {
 		/* if no buffer left we can free the stream. */
 		qc_stream_desc_free(stream, 0);
 	}
-	else {
-		/* A released stream does not use <stream.buf>. */
-		stream->buf = NULL;
-	}
 }
 
 /* Acknowledge data at <offset> of length <len> for <stream>. It is handled
diff --git a/src/quic_tls.c b/src/quic_tls.c
index 7e18a3926..581d615ce 100644
--- a/src/quic_tls.c
+++ b/src/quic_tls.c
@@ -125,7 +125,7 @@ void quic_cstream_free(struct quic_cstream *cs)
 
 	quic_free_ncbuf(&cs->rx.ncbuf);
 
-	qc_stream_desc_release(cs->desc);
+	qc_stream_desc_release(cs->desc, 0);
 	pool_free(pool_head_quic_cstream, cs);
 }