diff --git a/libavcodec/sonic.c b/libavcodec/sonic.c
index 9498919d2f..d902beb501 100644
--- a/libavcodec/sonic.c
+++ b/libavcodec/sonic.c
@@ -1018,7 +1018,7 @@ static int sonic_decode_frame(AVCodecContext *avctx,
 
     // dequantize
     for (i = 0; i < s->num_taps; i++)
-        s->predictor_k[i] *= s->tap_quant[i];
+        s->predictor_k[i] *= (unsigned) s->tap_quant[i];
 
     if (s->lossless)
         quant = 1;