diff --git a/player.h b/player.h
index 12563bfe..35383590 100644
--- a/player.h
+++ b/player.h
@@ -11,10 +11,7 @@ typedef struct {
 typedef uint16_t seq_t;
 
 // wrapped number between two seq_t.
-static inline uint16_t seq_diff(seq_t a, seq_t b) {
-    int16_t diff = b - a;
-    return diff;
-}
+inline int32_t seq_diff(seq_t a, seq_t b);
 
 int player_play(stream_cfg *cfg);
 void player_stop(void);