diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
index 7a87aa36f0..1bb778f6a5 100644
--- a/libavcodec/wavpack.c
+++ b/libavcodec/wavpack.c
@@ -219,7 +219,7 @@ static int wv_get_value(WavpackFrameContext *ctx, GetBitContext *gb,
         INC_MED(1);
         DEC_MED(2);
     } else {
-        base = GET_MED(0) + GET_MED(1) + GET_MED(2) * (t - 2);
+        base = GET_MED(0) + GET_MED(1) + GET_MED(2) * (t - 2U);
         add  = GET_MED(2) - 1;
         INC_MED(0);
         INC_MED(1);