diff --git a/libavutil/mathematics.c b/libavutil/mathematics.c
index 16e4eba5b9..fde460cc3e 100644
--- a/libavutil/mathematics.c
+++ b/libavutil/mathematics.c
@@ -52,7 +52,7 @@ int64_t av_gcd(int64_t a, int64_t b) {
         v -= u;
         v >>= ff_ctzll(v);
     }
-    return u << k;
+    return (uint64_t)u << k;
 }
 
 int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd)