diff --git a/include/haproxy/xprt_quic-t.h b/include/haproxy/xprt_quic-t.h
index 78ced5160..98a0ea709 100644
--- a/include/haproxy/xprt_quic-t.h
+++ b/include/haproxy/xprt_quic-t.h
@@ -306,6 +306,7 @@ struct preferred_address {
 #define QUIC_TP_PREFERRED_ADDRESS                   13
 #define QUIC_TP_ACTIVE_CONNECTION_ID_LIMIT          14
 #define QUIC_TP_INITIAL_SOURCE_CONNECTION_ID        15
+#define QUIC_TP_RETRY_SOURCE_CONNECTION_ID          16
 
 /*
  * These defines are not for transport parameter type, but the maximum accepted value for
@@ -346,6 +347,10 @@ struct quic_transport_params {
 	 * When received by clients, must be set to 1 if present.
 	 */
 	struct quic_cid original_destination_connection_id;            /* Forbidden for clients */
+	/*
+	 * MUST be sent by servers after Retry.
+	 */
+	struct quic_cid retry_source_connection_id;                    /* Forbidden for clients */
 	/* MUST be present both for servers and clients. */
 	struct quic_cid initial_source_connection_id;
 	struct preferred_address preferred_address;                    /* Forbidden for clients */
diff --git a/include/haproxy/xprt_quic.h b/include/haproxy/xprt_quic.h
index 2c41355ba..9e76c7594 100644
--- a/include/haproxy/xprt_quic.h
+++ b/include/haproxy/xprt_quic.h
@@ -488,6 +488,8 @@ static inline void quic_transport_params_init(struct quic_transport_params *p,
 		p->with_stateless_reset_token      = 1;
 	p->active_connection_id_limit          = 8;
 
+	p->retry_source_connection_id.len = 0;
+
 }
 
 /* Encode <addr> preferred address transport parameter in <buf> without its
@@ -779,6 +781,15 @@ static inline int quic_transport_params_encode(unsigned char *buf,
 		                                  p->original_destination_connection_id.data,
 		                                  p->original_destination_connection_id.len))
 			return 0;
+
+		if (p->retry_source_connection_id.len) {
+			if (!quic_transport_param_enc_mem(&pos, end,
+			                                  QUIC_TP_RETRY_SOURCE_CONNECTION_ID,
+			                                  p->retry_source_connection_id.data,
+			                                  p->retry_source_connection_id.len))
+				return 0;
+		}
+
 		if (p->with_stateless_reset_token &&
 			!quic_transport_param_enc_mem(&pos, end, QUIC_TP_STATELESS_RESET_TOKEN,
 			                              p->stateless_reset_token,
diff --git a/src/xprt_quic.c b/src/xprt_quic.c
index 6cf0d4bb7..83379d097 100644
--- a/src/xprt_quic.c
+++ b/src/xprt_quic.c
@@ -4198,6 +4198,9 @@ static ssize_t qc_lstnr_pkt_rcv(unsigned char *buf, const unsigned char *end,
 					TRACE_PROTO("Error during Initial token parsing", QUIC_EV_CONN_LPKT, qc);
 					goto err;
 				}
+				/* Copy retry_source_connection_id transport parameter. */
+				quic_cid_cpy(&qc->rx.params.retry_source_connection_id,
+				             &pkt->dcid);
 			}
 			else {
 				memcpy(odcid->data, &pkt->dcid.data, pkt->dcid.len);