diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index d6b87db734..2f44340661 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -486,7 +486,7 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
 static int allocate_buffers(ALACContext *alac)
 {
     int ch;
-    int buf_size = alac->max_samples_per_frame * sizeof(int32_t);
+    unsigned buf_size = alac->max_samples_per_frame * sizeof(int32_t);
 
     for (ch = 0; ch < 2; ch++) {
         alac->predict_error_buffer[ch]  = NULL;