diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
index a4f05f094f..70625548eb 100644
--- a/libavcodec/wavpack.c
+++ b/libavcodec/wavpack.c
@@ -474,7 +474,7 @@ static inline int wv_unpack_stereo(WavpackFrameContext *s, GetBitContext *gb,
         }
 
         if (type == AV_SAMPLE_FMT_S16P) {
-            if (FFABS(L) + FFABS(R) > (1<<19)) {
+            if (FFABS(L) + (unsigned)FFABS(R) > (1<<19)) {
                 av_log(s->avctx, AV_LOG_ERROR, "sample %d %d too large\n", L, R);
                 return AVERROR_INVALIDDATA;
             }