diff --git a/libavcodec/truemotion2.c b/libavcodec/truemotion2.c
index d59095622d..4e3a429777 100644
--- a/libavcodec/truemotion2.c
+++ b/libavcodec/truemotion2.c
@@ -668,7 +668,7 @@ static inline void tm2_still_block(TM2Context *ctx, AVFrame *pic, int bx, int by
 static inline void tm2_update_block(TM2Context *ctx, AVFrame *pic, int bx, int by)
 {
     int i, j;
-    int d;
+    unsigned d;
     TM2_INIT_POINTERS_2();
 
     /* update chroma */