diff --git a/boring-sys/patches/boring-pq.patch b/boring-sys/patches/boring-pq.patch
index fb5df8b9..1f13962a 100644
--- a/boring-sys/patches/boring-pq.patch
+++ b/boring-sys/patches/boring-pq.patch
@@ -503,7 +503,7 @@ index d3ea02090..ccb5b3d9b 100644
 +  for(i=0;i<len;i++)
 +    r |= a[i] ^ b[i];
 +
-+  return (-(uint64_t)r) >> 63;
++  return (0-(uint64_t)r) >> 63;
 +}
 +
 +/*************************************************