diff --git a/libavcodec/audiodsp.c b/libavcodec/audiodsp.c
index 3c7a3a7583..efcb0a8e8a 100644
--- a/libavcodec/audiodsp.c
+++ b/libavcodec/audiodsp.c
@@ -79,7 +79,7 @@ static void vector_clipf_c(float *dst, const float *src, int len,
 static int32_t scalarproduct_int16_c(const int16_t *v1, const int16_t *v2,
                                      int order)
 {
-    int res = 0;
+    unsigned res = 0;
 
     while (order--)
         res += *v1++ **v2++;