diff --git a/src/modules/module-netjack2/packets.h b/src/modules/module-netjack2/packets.h
index c7e92fc62..dc530d041 100644
--- a/src/modules/module-netjack2/packets.h
+++ b/src/modules/module-netjack2/packets.h
@@ -133,7 +133,7 @@ struct nj2_packet_header {
 
 static inline void nj2_dump_packet_header(struct nj2_packet_header *header)
 {
-	pw_log_info("Type:         %s", header->type);
+	pw_log_info("Type:         %.*s", (int)sizeof(header->type), header->type);
 	pw_log_info("Data Type:    %c", ntohl(header->data_type));
 	pw_log_info("Data Stream:  %c", ntohl(header->data_stream));
 	pw_log_info("ID:           %u", ntohl(header->id));
diff --git a/src/modules/module-netjack2/peer.c b/src/modules/module-netjack2/peer.c
index ba2e10741..3a69a083c 100644
--- a/src/modules/module-netjack2/peer.c
+++ b/src/modules/module-netjack2/peer.c
@@ -156,6 +156,12 @@ static int netjack2_init(struct netjack2_peer *peer)
 		errno = EINVAL;
 		goto error_errno;
 	}
+	if (peer->params.mtu < UDP_HEADER_SIZE + sizeof(struct nj2_packet_header) ||
+	    sizeof(struct nj2_packet_header) +
+		    peer->params.recv_audio_channels * sizeof(int32_t) > peer->params.mtu) {
+		errno = EINVAL;
+		goto error_errno;
+	}
 
 	if (peer->params.sample_encoder == NJ2_ENCODER_INT) {
 		if (spa_overflow_mul(peer->params.period_size, (uint32_t)sizeof(int16_t), &peer->max_encoded_size) ||