diff --git a/include/haproxy/quic_conn-t.h b/include/haproxy/quic_conn-t.h
index 4100e3061..75493915d 100644
--- a/include/haproxy/quic_conn-t.h
+++ b/include/haproxy/quic_conn-t.h
@@ -145,6 +145,9 @@ enum quic_pkt_type {
 #define QUIC_PACKET_PNL_BITMASK      0x03
 #define QUIC_PACKET_PN_MAXLEN        4
 
+/* TLS algo supported by QUIC uses a 16-bytes sample for HP. */
+#define QUIC_HP_SAMPLE_LEN           16
+
 /*
  *  0                   1                   2                   3
  *  0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
diff --git a/src/quic_tx.c b/src/quic_tx.c
index 7a2da7eed..10a6c5e65 100644
--- a/src/quic_tx.c
+++ b/src/quic_tx.c
@@ -1998,8 +1998,8 @@ static int qc_do_build_pkt(unsigned char *pos, const unsigned char *end,
 	 * Note that from here, <len> includes <*pn_len>, the total frame lenghts,
 	 * and QUIC_TLS_TAG_LEN(16).
 	 */
-	if (len < QUIC_PACKET_PN_MAXLEN + QUIC_TLS_TAG_LEN) {
-		padding_len = QUIC_PACKET_PN_MAXLEN + QUIC_TLS_TAG_LEN - len;
+	if (len < QUIC_PACKET_PN_MAXLEN + QUIC_HP_SAMPLE_LEN) {
+		padding_len = QUIC_PACKET_PN_MAXLEN + QUIC_HP_SAMPLE_LEN - len;
 		TRACE_PRINTF(TRACE_LEVEL_DEVELOPER, QUIC_EV_CONN_PHPKTS, qc, 0, 0, 0,
 		             "adding padding pn=%llu padding_len=%zu *pn_len=%zu"
 		             " len=%zu len_frms=%zu",