Index: src/runtime/arc.m
==================================================================
--- src/runtime/arc.m
+++ src/runtime/arc.m
@@ -65,11 +65,11 @@
 }
 
 id
 objc_retainBlock(id block)
 {
-	return (id)_Block_copy(block);
+	return [block copy];
 }
 
 id
 objc_retainAutorelease(id object)
 {