diff --git a/include/haproxy/h2.h b/include/haproxy/h2.h
index 45c3d8f10..6bf9df9cc 100644
--- a/include/haproxy/h2.h
+++ b/include/haproxy/h2.h
@@ -179,6 +179,7 @@ enum h2_err {
 #define H2_MSGF_RSP_1XX        0x0010    // a 1xx ( != 101) HEADERS frame was received
 #define H2_MSGF_BODYLESS_RSP   0x0020    // response message is known to have no body
                                          // (response to HEAD request or 204/304 response)
+#define H2_MSGF_EXT_CONNECT    0x0040    // Extented CONNECT method from rfc 8441
 
 #define H2_MAX_STREAM_ID       ((1U << 31) - 1)
 #define H2_MAX_FRAME_LEN       ((1U << 24) - 1)
@@ -204,7 +205,7 @@ extern struct h2_frame_definition h2_frame_definition[H2_FT_ENTRIES];
 
 int h2_parse_cont_len_header(unsigned int *msgf, struct ist *value, unsigned long long *body_len);
 int h2_make_htx_request(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len);
-int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len);
+int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, char *upgrade_protocol);
 int h2_make_htx_trailers(struct http_hdr *list, struct htx *htx);
 
 /*
diff --git a/src/h2.c b/src/h2.c
index a4279d324..9154bd50d 100644
--- a/src/h2.c
+++ b/src/h2.c
@@ -529,7 +529,7 @@ static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr,
 {
 	unsigned int status, flags = HTX_SL_F_NONE;
 	struct htx_sl *sl;
-	unsigned char h, t, u;
+	struct ist stat;
 
 	/* only :status is allowed as a pseudo header */
 	if (!(fields & H2_PHDR_FND_STAT))
@@ -538,12 +538,25 @@ static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr,
 	if (phdr[H2_PHDR_IDX_STAT].len != 3)
 		goto fail;
 
-	h = phdr[H2_PHDR_IDX_STAT].ptr[0] - '0';
-	t = phdr[H2_PHDR_IDX_STAT].ptr[1] - '0';
-	u = phdr[H2_PHDR_IDX_STAT].ptr[2] - '0';
-	if (h > 9 || t > 9 || u > 9)
-		goto fail;
-	status = h * 100 + t * 10 + u;
+	/* if Extended CONNECT is used, convert status code from 200 to htx 101
+	 * following rfc 8441 */
+	if (unlikely(*msgf & H2_MSGF_EXT_CONNECT) &&
+	    isteq(phdr[H2_PHDR_IDX_STAT], ist("200"))) {
+		stat = ist("101");
+		status = 101;
+	}
+	else {
+		unsigned char h, t, u;
+
+		stat = phdr[H2_PHDR_IDX_STAT];
+
+		h = stat.ptr[0] - '0';
+		t = stat.ptr[1] - '0';
+		u = stat.ptr[2] - '0';
+		if (h > 9 || t > 9 || u > 9)
+			goto fail;
+		status = h * 100 + t * 10 + u;
+	}
 
 	/* 101 responses are not supported in H2, so return a error.
 	 * On 1xx responses there is no ES on the HEADERS frame but there is no
@@ -551,14 +564,20 @@ static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr,
 	 * notify the decoder another HEADERS frame is expected.
 	 * 204/304 resposne have no body by definition. So remove the flag
 	 * H2_MSGF_BODY and set H2_MSGF_BODYLESS_RSP.
+	 *
+	 * Note however that there is a special condition for Extended CONNECT.
+	 * In this case, we explicitly convert it to HTX 101 to mimic
+	 * Get+Upgrade HTTP/1.1 mechanism
 	 */
-	if (status == 101)
-		goto fail;
+	if (status == 101) {
+		if (!(*msgf & H2_MSGF_EXT_CONNECT))
+			goto fail;
+	}
 	else if (status < 200) {
 		*msgf |= H2_MSGF_RSP_1XX;
 		*msgf &= ~H2_MSGF_BODY;
 	}
-	else if (sl->info.res.status == 204 || sl->info.res.status == 304) {
+	else if (status == 204 || status == 304) {
 		*msgf &= ~H2_MSGF_BODY;
 		*msgf |= H2_MSGF_BODYLESS_RSP;
 	}
@@ -567,7 +586,7 @@ static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr,
 	flags |= HTX_SL_F_VER_11;    // V2 in fact
 	flags |= HTX_SL_F_XFER_LEN;  // xfer len always known with H2
 
-	sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, ist("HTTP/2.0"), phdr[H2_PHDR_IDX_STAT], ist(""));
+	sl = htx_add_stline(htx, HTX_BLK_RES_SL, flags, ist("HTTP/2.0"), stat, ist(""));
 	if (!sl)
 		goto fail;
 	sl->info.res.status = status;
@@ -593,8 +612,11 @@ static struct htx_sl *h2_prepare_htx_stsline(uint32_t fields, struct ist *phdr,
  *   - n.name ignored, n.len == 0 : end of list
  *   - in all cases except the end of list, v.name and v.len must designate a
  *     valid value.
+ *
+ * <upgrade_protocol> is only used if the htx status code is 101 indicating a
+ * response to an upgrade or h2-equivalent request.
  */
-int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len)
+int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *msgf, unsigned long long *body_len, char *upgrade_protocol)
 {
 	struct ist phdr_val[H2_PHDR_NUM_ENTRIES];
 	uint32_t fields; /* bit mask of H2_PHDR_FND_* */
@@ -698,7 +720,16 @@ int h2_make_htx_response(struct http_hdr *list, struct htx *htx, unsigned int *m
 			goto fail;
 	}
 
-	if ((*msgf & H2_MSGF_BODY_TUNNEL) && sl->info.res.status >= 200 && sl->info.res.status < 300)
+	if (sl->info.res.status == 101 && upgrade_protocol) {
+		if (!htx_add_header(htx, ist("connection"), ist("upgrade")))
+			goto fail;
+		if (!htx_add_header(htx, ist("upgrade"), ist(upgrade_protocol)))
+			goto fail;
+		sl_flags |= HTX_SL_F_CONN_UPG;
+	}
+
+	if ((*msgf & H2_MSGF_BODY_TUNNEL) &&
+	    ((sl->info.res.status >= 200 && sl->info.res.status < 300) || sl->info.res.status == 101))
 		*msgf &= ~(H2_MSGF_BODY|H2_MSGF_BODY_CL);
 	else
 		*msgf &= ~H2_MSGF_BODY_TUNNEL;
diff --git a/src/mux_h2.c b/src/mux_h2.c
index 3565b7a19..a9218308b 100644
--- a/src/mux_h2.c
+++ b/src/mux_h2.c
@@ -217,6 +217,8 @@ struct h2s {
 	struct list list; /* To be used when adding in h2c->send_list or h2c->fctl_lsit */
 	struct tasklet *shut_tl;  /* deferred shutdown tasklet, to retry to send an RST after we failed to,
 				   * in case there's no other subscription to do it */
+
+	char upgrade_protocol[16]; /* rfc 8441: requested protocol on Extended CONNECT */
 };
 
 /* descriptor for an h2 frame header */
@@ -555,7 +557,7 @@ static int h2_process(struct h2c *h2c);
 /* h2_io_cb is exported to see it resolved in "show fd" */
 struct task *h2_io_cb(struct task *t, void *ctx, unsigned short state);
 static inline struct h2s *h2c_st_by_id(struct h2c *h2c, int id);
-static int h2c_decode_headers(struct h2c *h2c, struct buffer *rxbuf, uint32_t *flags, unsigned long long *body_len);
+static int h2c_decode_headers(struct h2c *h2c, struct buffer *rxbuf, uint32_t *flags, unsigned long long *body_len, char *upgrade_protocol);
 static int h2_frt_transfer_data(struct h2s *h2s);
 static struct task *h2_deferred_shut(struct task *t, void *ctx, unsigned short state);
 static struct h2s *h2c_bck_stream_new(struct h2c *h2c, struct conn_stream *cs, struct session *sess);
@@ -1443,6 +1445,7 @@ static struct h2s *h2s_new(struct h2c *h2c, int id)
 	h2s->status    = 0;
 	h2s->body_len  = 0;
 	h2s->rxbuf     = BUF_NULL;
+	memset(h2s->upgrade_protocol, 0, sizeof(h2s->upgrade_protocol));
 
 	h2s->by_id.key = h2s->id = id;
 	if (id > 0)
@@ -2617,7 +2620,7 @@ static struct h2s *h2c_frt_handle_headers(struct h2c *h2c, struct h2s *h2s)
 	if (h2s->st != H2_SS_IDLE) {
 		/* The stream exists/existed, this must be a trailers frame */
 		if (h2s->st != H2_SS_CLOSED) {
-			error = h2c_decode_headers(h2c, &h2s->rxbuf, &h2s->flags, &body_len);
+			error = h2c_decode_headers(h2c, &h2s->rxbuf, &h2s->flags, &body_len, NULL);
 			/* unrecoverable error ? */
 			if (h2c->st0 >= H2_CS_ERROR)
 				goto out;
@@ -2638,7 +2641,7 @@ static struct h2s *h2c_frt_handle_headers(struct h2c *h2c, struct h2s *h2s)
 		/* the connection was already killed by an RST, let's consume
 		 * the data and send another RST.
 		 */
-		error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len);
+		error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len, NULL);
 		h2s = (struct h2s*)h2_error_stream;
 		goto send_rst;
 	}
@@ -2653,7 +2656,7 @@ static struct h2s *h2c_frt_handle_headers(struct h2c *h2c, struct h2s *h2s)
 	else if (h2c->flags & H2_CF_DEM_TOOMANY)
 		goto out; // IDLE but too many cs still present
 
-	error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len);
+	error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len, NULL);
 
 	/* unrecoverable error ? */
 	if (h2c->st0 >= H2_CS_ERROR)
@@ -2748,13 +2751,13 @@ static struct h2s *h2c_bck_handle_headers(struct h2c *h2c, struct h2s *h2s)
 		goto fail; // incomplete frame
 
 	if (h2s->st != H2_SS_CLOSED) {
-		error = h2c_decode_headers(h2c, &h2s->rxbuf, &h2s->flags, &h2s->body_len);
+		error = h2c_decode_headers(h2c, &h2s->rxbuf, &h2s->flags, &h2s->body_len, h2s->upgrade_protocol);
 	}
 	else {
 		/* the connection was already killed by an RST, let's consume
 		 * the data and send another RST.
 		 */
-		error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len);
+		error = h2c_decode_headers(h2c, &rxbuf, &flags, &body_len, NULL);
 		h2s = (struct h2s*)h2_error_stream;
 		h2c->st0 = H2_CS_FRAME_E;
 		goto send_rst;
@@ -4522,7 +4525,7 @@ static void h2_shutw(struct conn_stream *cs, enum cs_shw_mode mode)
  * decoding, in order to detect if we're dealing with a headers or a trailers
  * block (the trailers block appears after H2_SF_HEADERS_RCVD was seen).
  */
-static int h2c_decode_headers(struct h2c *h2c, struct buffer *rxbuf, uint32_t *flags, unsigned long long *body_len)
+static int h2c_decode_headers(struct h2c *h2c, struct buffer *rxbuf, uint32_t *flags, unsigned long long *body_len, char *upgrade_protocol)
 {
 	const uint8_t *hdrs = (uint8_t *)b_head(&h2c->dbuf);
 	struct buffer *tmp = get_trash_chunk();
@@ -4679,13 +4682,16 @@ next_frame:
 	/* OK now we have our header list in <list> */
 	msgf = (h2c->dff & H2_F_HEADERS_END_STREAM) ? 0 : H2_MSGF_BODY;
 	msgf |= (*flags & H2_SF_BODY_TUNNEL) ? H2_MSGF_BODY_TUNNEL: 0;
+	/* If an Extended CONNECT has been sent on this stream, set message flag
+	 * to convert 200 response to 101 htx reponse */
+	msgf |= (*flags & H2_SF_EXT_CONNECT_SENT) ? H2_MSGF_EXT_CONNECT: 0;
 
 	if (*flags & H2_SF_HEADERS_RCVD)
 		goto trailers;
 
 	/* This is the first HEADERS frame so it's a headers block */
 	if (h2c->flags & H2_CF_IS_BACK)
-		outlen = h2_make_htx_response(list, htx, &msgf, body_len);
+		outlen = h2_make_htx_response(list, htx, &msgf, body_len, upgrade_protocol);
 	else
 		outlen = h2_make_htx_request(list, htx, &msgf, body_len);