diff --git a/src/quic_frame.c b/src/quic_frame.c
index 450fdd99..4f07462 100644
--- a/src/quic_frame.c
+++ b/src/quic_frame.c
@@ -859,40 +859,41 @@
 	int (*func)(unsigned char **buf, const unsigned char *end,
                  struct quic_frame *frm, struct quic_conn *conn);
 	unsigned char flags;
+	unsigned char mask;
 };
 
 struct quic_frame_builder quic_frame_builders[] = {
-	[QUIC_FT_PADDING]              = { .func = quic_build_padding_frame,              .flags = QUIC_FL_TX_PACKET_PADDING, },
-	[QUIC_FT_PING]                 = { .func = quic_build_ping_frame,                 .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_ACK]                  = { .func = quic_build_ack_frame,                  .flags = 0, },
-	[QUIC_FT_ACK_ECN]              = { .func = quic_build_ack_ecn_frame,              .flags = 0, },
-	[QUIC_FT_RESET_STREAM]         = { .func = quic_build_reset_stream_frame,         .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STOP_SENDING]         = { .func = quic_build_stop_sending_frame,         .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_CRYPTO]               = { .func = quic_build_crypto_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_NEW_TOKEN]            = { .func = quic_build_new_token_frame,            .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_8]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_9]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_A]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_B]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_C]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_D]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_E]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_F]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_MAX_DATA]             = { .func = quic_build_max_data_frame,             .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_MAX_STREAM_DATA]      = { .func = quic_build_max_stream_data_frame,      .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_MAX_STREAMS_BIDI]     = { .func = quic_build_max_streams_bidi_frame,     .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_MAX_STREAMS_UNI]      = { .func = quic_build_max_streams_uni_frame,      .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_DATA_BLOCKED]         = { .func = quic_build_data_blocked_frame,         .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAM_DATA_BLOCKED]  = { .func = quic_build_stream_data_blocked_frame,  .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAMS_BLOCKED_BIDI] = { .func = quic_build_streams_blocked_bidi_frame, .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_STREAMS_BLOCKED_UNI]  = { .func = quic_build_streams_blocked_uni_frame,  .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_NEW_CONNECTION_ID]    = { .func = quic_build_new_connection_id_frame,    .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_RETIRE_CONNECTION_ID] = { .func = quic_build_retire_connection_id_frame, .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_PATH_CHALLENGE]       = { .func = quic_build_path_challenge_frame,       .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_PATH_RESPONSE]        = { .func = quic_build_path_response_frame,        .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
-	[QUIC_FT_CONNECTION_CLOSE]     = { .func = quic_build_connection_close_frame,     .flags = 0, },
-	[QUIC_FT_CONNECTION_CLOSE_APP] = { .func = quic_build_connection_close_app_frame, .flags = 0, },
-	[QUIC_FT_HANDSHAKE_DONE]       = { .func = quic_build_handshake_done_frame,       .flags = QUIC_FL_TX_PACKET_ACK_ELICITING, },
+	[QUIC_FT_PADDING]              = { .func = quic_build_padding_frame,              .flags = 0,                               .mask = QUIC_FT_PKT_TYPE_IH01_BITMASK, },
+	[QUIC_FT_PING]                 = { .func = quic_build_ping_frame,                 .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE_IH01_BITMASK, },
+	[QUIC_FT_ACK]                  = { .func = quic_build_ack_frame,                  .flags = 0,                               .mask = QUIC_FT_PKT_TYPE_IH_1_BITMASK, },
+	[QUIC_FT_ACK_ECN]              = { .func = quic_build_ack_ecn_frame,              .flags = 0,                               .mask = QUIC_FT_PKT_TYPE_IH_1_BITMASK, },
+	[QUIC_FT_RESET_STREAM]         = { .func = quic_build_reset_stream_frame,         .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STOP_SENDING]         = { .func = quic_build_stop_sending_frame,         .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_CRYPTO]               = { .func = quic_build_crypto_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE_IH_1_BITMASK, },
+	[QUIC_FT_NEW_TOKEN]            = { .func = quic_build_new_token_frame,            .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE____1_BITMASK, },
+	[QUIC_FT_STREAM_8]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_9]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_A]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_B]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_C]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_D]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_E]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_F]             = { .func = quic_build_stream_frame,               .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_MAX_DATA]             = { .func = quic_build_max_data_frame,             .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_MAX_STREAM_DATA]      = { .func = quic_build_max_stream_data_frame,      .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_MAX_STREAMS_BIDI]     = { .func = quic_build_max_streams_bidi_frame,     .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_MAX_STREAMS_UNI]      = { .func = quic_build_max_streams_uni_frame,      .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_DATA_BLOCKED]         = { .func = quic_build_data_blocked_frame,         .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAM_DATA_BLOCKED]  = { .func = quic_build_stream_data_blocked_frame,  .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAMS_BLOCKED_BIDI] = { .func = quic_build_streams_blocked_bidi_frame, .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_STREAMS_BLOCKED_UNI]  = { .func = quic_build_streams_blocked_uni_frame,  .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_NEW_CONNECTION_ID]    = { .func = quic_build_new_connection_id_frame,    .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_RETIRE_CONNECTION_ID] = { .func = quic_build_retire_connection_id_frame, .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_PATH_CHALLENGE]       = { .func = quic_build_path_challenge_frame,       .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_PATH_RESPONSE]        = { .func = quic_build_path_response_frame,        .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_CONNECTION_CLOSE]     = { .func = quic_build_connection_close_frame,     .flags = 0,                               .mask = QUIC_FT_PKT_TYPE_IH01_BITMASK, },
+	[QUIC_FT_CONNECTION_CLOSE_APP] = { .func = quic_build_connection_close_app_frame, .flags = 0,                               .mask = QUIC_FT_PKT_TYPE___01_BITMASK, },
+	[QUIC_FT_HANDSHAKE_DONE]       = { .func = quic_build_handshake_done_frame,       .flags = QUIC_FL_RX_PACKET_ACK_ELICITING, .mask = QUIC_FT_PKT_TYPE____1_BITMASK, },
 };
 
 struct quic_frame_parser {
@@ -982,6 +983,13 @@
 {
 	struct quic_frame_builder *builder;
 
+	builder = &quic_frame_builders[frm->type];
+	if (!(builder->mask & (1 << pkt->type))) {
+		/* XXX This it a bug to send an unauthorized frame with such a packet type XXX */
+		TRACE_DEVEL("frame skipped", QUIC_EV_CONN_BFRM, conn->conn, frm);
+		BUG_ON(!(builder->mask & (1 << pkt->type)));
+	}
+
 	if (end <= *buf) {
 		TRACE_DEVEL("not enough room", QUIC_EV_CONN_BFRM, conn->conn, frm);
 		return 0;
@@ -989,7 +997,6 @@
 
 	TRACE_PROTO("frame", QUIC_EV_CONN_BFRM, conn->conn, frm);
 	*(*buf)++ = frm->type;
-	builder = &quic_frame_builders[frm->type];
 	if (!quic_frame_builders[frm->type].func(buf, end, frm, conn)) {
 		TRACE_DEVEL("frame building error", QUIC_EV_CONN_BFRM, conn->conn, frm);
 		return 0;