diff --git a/include/haproxy/h3.h b/include/haproxy/h3.h
index 504e9bfed..ab088d86a 100644
--- a/include/haproxy/h3.h
+++ b/include/haproxy/h3.h
@@ -111,7 +111,5 @@ enum h3s_st_req {
 
 extern const struct qcc_app_ops h3_ops;
 
-size_t h3_snd_buf(struct stconn *sc, struct buffer *buf, size_t count, int flags);
-
 #endif /* USE_QUIC */
 #endif /* _HAPROXY_H3_T_H */
diff --git a/include/haproxy/mux_quic-t.h b/include/haproxy/mux_quic-t.h
index 1670262a1..43ea53044 100644
--- a/include/haproxy/mux_quic-t.h
+++ b/include/haproxy/mux_quic-t.h
@@ -185,7 +185,7 @@ struct qcc_app_ops {
 	int (*init)(struct qcc *qcc);
 	int (*attach)(struct qcs *qcs, void *conn_ctx);
 	ssize_t (*decode_qcs)(struct qcs *qcs, struct buffer *b, int fin);
-	size_t (*snd_buf)(struct stconn *sc, struct buffer *buf, size_t count, int flags);
+	size_t (*snd_buf)(struct qcs *qcs, struct buffer *buf, size_t count, int flags);
 	void (*detach)(struct qcs *qcs);
 	int (*finalize)(void *ctx);
 	void (*shutdown)(void *ctx);                    /* Close a connection. */
diff --git a/src/h3.c b/src/h3.c
index 8d13f5d09..187c6065b 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -31,7 +31,6 @@
 #include <haproxy/qpack-dec.h>
 #include <haproxy/qpack-enc.h>
 #include <haproxy/quic_enc.h>
-#include <haproxy/stconn.h>
 #include <haproxy/tools.h>
 #include <haproxy/trace.h>
 #include <haproxy/xprt_quic.h>
@@ -1013,10 +1012,9 @@ static int h3_resp_data_send(struct qcs *qcs, struct buffer *buf, size_t count)
 	return total;
 }
 
-size_t h3_snd_buf(struct stconn *sc, struct buffer *buf, size_t count, int flags)
+static size_t h3_snd_buf(struct qcs *qcs, struct buffer *buf, size_t count, int flags)
 {
 	size_t total = 0;
-	struct qcs *qcs = __sc_mux_strm(sc);
 	struct htx *htx;
 	enum htx_blk_type btype;
 	struct htx_blk *blk;
diff --git a/src/hq_interop.c b/src/hq_interop.c
index be0287f6f..a133cd53b 100644
--- a/src/hq_interop.c
+++ b/src/hq_interop.c
@@ -12,7 +12,6 @@ static ssize_t hq_interop_decode_qcs(struct qcs *qcs, struct buffer *b, int fin)
 {
 	struct htx *htx;
 	struct htx_sl *sl;
-	struct stconn *sc;
 	struct buffer htx_buf = BUF_NULL;
 	struct ist path;
 	char *ptr = b_head(b);
@@ -70,8 +69,7 @@ static ssize_t hq_interop_decode_qcs(struct qcs *qcs, struct buffer *b, int fin)
 	htx_add_endof(htx, HTX_BLK_EOH);
 	htx_to_buf(htx, &htx_buf);
 
-	sc = qc_attach_sc(qcs, &htx_buf);
-	if (!sc)
+	if (!qc_attach_sc(qcs, &htx_buf))
 		return -1;
 
 	b_free(&htx_buf);
@@ -90,10 +88,9 @@ static struct buffer *mux_get_buf(struct qcs *qcs)
 	return &qcs->tx.buf;
 }
 
-static size_t hq_interop_snd_buf(struct stconn *sc, struct buffer *buf,
+static size_t hq_interop_snd_buf(struct qcs *qcs, struct buffer *buf,
                                  size_t count, int flags)
 {
-	struct qcs *qcs = __sc_mux_strm(sc);
 	struct htx *htx;
 	enum htx_blk_type btype;
 	struct htx_blk *blk;
diff --git a/src/mux_quic.c b/src/mux_quic.c
index 08db5387e..5b4a35469 100644
--- a/src/mux_quic.c
+++ b/src/mux_quic.c
@@ -2225,7 +2225,7 @@ static size_t qc_snd_buf(struct stconn *sc, struct buffer *buf,
 		goto end;
 	}
 
-	ret = qcs->qcc->app_ops->snd_buf(sc, buf, count, flags);
+	ret = qcs->qcc->app_ops->snd_buf(qcs, buf, count, flags);
 
  end:
 	TRACE_LEAVE(QMUX_EV_STRM_SEND, qcs->qcc->conn, qcs);