Use 'magick_restrict' instead of 'restrict'.
diff --git a/MagickWand/pixel-iterator.c b/MagickWand/pixel-iterator.c
index 12b60d4..684f21a 100644
--- a/MagickWand/pixel-iterator.c
+++ b/MagickWand/pixel-iterator.c
@@ -922,7 +922,7 @@
     x;
 
   register Quantum
-    *restrict pixels;
+    *_magickcore_restrict pixels;
 
   assert(iterator != (const PixelIterator *) NULL);
   assert(iterator->signature == MagickWandSignature);