diff --git a/src/video/SDL_surface.c b/src/video/SDL_surface.c
index a077974df..4585f2366 100644
--- a/src/video/SDL_surface.c
+++ b/src/video/SDL_surface.c
@@ -568,6 +568,7 @@ SDL_FillRect(SDL_Surface * dst, SDL_Rect * dstrect, Uint32 color)
         dstrect->x * dst->format->BytesPerPixel;
     if (dst->format->palette || (color == 0)) {
         x = dstrect->w * dst->format->BytesPerPixel;
+#ifndef __MACOSX__  /* memset() is optimized on Mac OS X */
         if (!color && !((uintptr_t) row & 3) && !(x & 3)
             && !(dst->pitch & 3)) {
             int n = x >> 2;
@@ -575,7 +576,9 @@ SDL_FillRect(SDL_Surface * dst, SDL_Rect * dstrect, Uint32 color)
                 SDL_memset4(row, 0, n);
                 row += dst->pitch;
             }
-        } else {
+        } else
+#endif /* !__MACOSX__ */
+        {
             for (y = dstrect->h; y; y--) {
                 SDL_memset(row, color, x);
                 row += dst->pitch;