Index: src/OFBlock.m
==================================================================
--- src/OFBlock.m
+++ src/OFBlock.m
@@ -145,11 +145,11 @@
 };
 
 struct class _NSConcreteStackBlock;
 struct class _NSConcreteGlobalBlock;
 struct class _NSConcreteMallocBlock;
-# ifdef __OBJC2__
+# if defined(__OBJC2__) && !defined(__ppc64__)
 struct class _NSConcreteStackBlock_metaclass;
 struct class _NSConcreteGlobalBlock_metaclass;
 struct class _NSConcreteMallocBlock_metaclass;
 # endif
 #endif
@@ -327,11 +327,11 @@
 #endif
 
 #ifdef OF_APPLE_RUNTIME
 	Class tmp;
 
-# ifdef __OBJC2__
+# if defined(__OBJC2__) && !defined(__ppc64__)
 	tmp = objc_initializeClassPair(self, "OFStackBlock",
 	    (Class)&_NSConcreteStackBlock,
 	    (Class)&_NSConcreteStackBlock_metaclass);
 	if (tmp == Nil)
 		@throw [OFInitializationFailedException