diff --git a/plugins/obs-outputs/flv-mux.c b/plugins/obs-outputs/flv-mux.c
index 6b6357e05..dc402930a 100644
--- a/plugins/obs-outputs/flv-mux.c
+++ b/plugins/obs-outputs/flv-mux.c
@@ -626,7 +626,7 @@ void flv_packet_metadata(enum video_id_t codec_id, uint8_t **output, size_t *siz
 	 * The default trackId is 0.
 	 */
 	if (is_multitrack) {
-		s_w8(&s, MULTITRACKTYPE_ONE_TRACK | PACKETTYPE_METADATA);
+		s_w8(&s, (uint8_t)MULTITRACKTYPE_ONE_TRACK | (uint8_t)PACKETTYPE_METADATA);
 		s_w4cc(&s, codec_id);
 		// trackId
 		s_w8(&s, (uint8_t)idx);