diff --git a/libavcodec/rectangle.h b/libavcodec/rectangle.h
index df7c18a4e2..9f982b2771 100644
--- a/libavcodec/rectangle.h
+++ b/libavcodec/rectangle.h
@@ -46,7 +46,7 @@ static av_always_inline void fill_rectangle(void *vp, int w, int h, int stride,
     w      *= size;
     stride *= size;
 
-    av_assert2((((long)vp)&(FFMIN(w, 8<<(HAVE_NEON|ARCH_PPC|HAVE_MMX))-1)) == 0);
+    av_assert2((((uintptr_t)vp)&(FFMIN(w, 8<<(HAVE_NEON|ARCH_PPC|HAVE_MMX))-1)) == 0);
     av_assert2((stride&(w-1))==0);
     if(w==2){
         const uint16_t v= size==4 ? val : val*0x0101;