diff --git a/src/h3.c b/src/h3.c
index fdad3b068..e0a1233d5 100644
--- a/src/h3.c
+++ b/src/h3.c
@@ -2123,6 +2123,15 @@ static int h3_req_headers_send(struct qcs *qcs, struct htx *htx)
 			goto err_full;
 	}
 
+	if (!(sl->flags & HTX_SL_F_XFER_LEN)) {
+		/* Extra care required for HTTP/1 responses without Content-Length nor
+		 * chunked encoding. In this case, shutw callback will be use to signal
+		 * the end of the message. QC_SF_UNKNOWN_PL_LENGTH is set to prevent a
+		 * RESET_STREAM emission in this case.
+		 */
+		qcs->flags |= QC_SF_UNKNOWN_PL_LENGTH;
+	}
+
 	/* Encode every parsed headers, stop at empty one. */
 	for (hdr = 0; hdr < sizeof(list) / sizeof(list[0]); ++hdr) {
 		if (isteq(list[hdr].n, ist("")))
@@ -2307,6 +2316,15 @@ static int h3_resp_headers_send(struct qcs *qcs, struct htx *htx)
 		goto err_full;
 	}
 
+	if (!(sl->flags & HTX_SL_F_XFER_LEN)) {
+		/* Extra care required for HTTP/1 responses without Content-Length nor
+		 * chunked encoding. In this case, shutw callback will be use to signal
+		 * the end of the message. QC_SF_UNKNOWN_PL_LENGTH is set to prevent a
+		 * RESET_STREAM emission in this case.
+		 */
+		qcs->flags |= QC_SF_UNKNOWN_PL_LENGTH;
+	}
+
 	for (hdr = 0; hdr < sizeof(list) / sizeof(list[0]); ++hdr) {
 		if (isteq(list[hdr].n, ist("")))
 			break;
diff --git a/src/qmux_http.c b/src/qmux_http.c
index 9a310a397..552e16821 100644
--- a/src/qmux_http.c
+++ b/src/qmux_http.c
@@ -95,23 +95,10 @@ int qcs_http_handle_standalone_fin(struct qcs *qcs)
 size_t qcs_http_snd_buf(struct qcs *qcs, struct buffer *buf, size_t count,
                         char *fin)
 {
-	struct htx *htx;
 	size_t ret;
 
 	TRACE_ENTER(QMUX_EV_STRM_SEND, qcs->qcc->conn, qcs);
-
-	htx = htxbuf(buf);
-
-	/* Extra care required for HTTP/1 responses without Content-Length nor
-	 * chunked encoding. In this case, shutw callback will be use to signal
-	 * the end of the message. QC_SF_UNKNOWN_PL_LENGTH is set to prevent a
-	 * RESET_STREAM emission in this case.
-	 */
-	if (htx->extra && htx->extra == HTX_UNKOWN_PAYLOAD_LENGTH)
-		qcs->flags |= QC_SF_UNKNOWN_PL_LENGTH;
-
 	ret = qcs->qcc->app_ops->snd_buf(qcs, buf, count, fin);
-
 	TRACE_LEAVE(QMUX_EV_STRM_SEND, qcs->qcc->conn, qcs);
 
 	return ret;