@@ -274,12 +274,15 @@
 			[Whether gcc atomic operations are available])
 		], [AC_MSG_RESULT(no)])
 
 	AC_CHECK_HEADER(libkern/OSAtomic.h, [
 		test x"$atomic_ops" = x"none" && atomic_ops="libkern/OSAtomic.h"
-		AC_DEFINE(OF_HAVE_LIBKERN_OSATOMIC_H, 1,
-			[Whether we have libkern/OSAtomic.h])])
+		AC_DEFINE(OF_HAVE_OSATOMIC, 1,
+			[Whether we have libkern/OSAtomic.h])
+		AC_CHECK_FUNC(OSAtomicAdd64Barrier, [
+			AC_DEFINE(OF_HAVE_OSATOMIC_64, 1,
+				[Whether we have OSAtomic*64])])])
 else
 	dnl We can only have one thread - therefore everything is atomic
 	atomic_ops="not needed"
 fi