--- xnu/xnu-2422.100.13/libkern/c++/OSMetaClass.cpp
+++ xnu/xnu-2050.9.2/libkern/c++/OSMetaClass.cpp
@@ -46,6 +46,8 @@
 #include <libkern/c++/OSLib.h>
 #include <libkern/OSAtomic.h>
 
+#include <IOKit/pwr_mgt/RootDomain.h>
+#include <IOKit/IOMessage.h>
 #include <IOKit/IOLib.h>
 
 __BEGIN_DECLS
@@ -813,10 +815,8 @@
 	    if (superClassLink) {
 		superClassLink->removeInstance(reserved->instances, true);
 	    }
-	    IOLockLock(sAllClassesLock);
 	    reserved->instances->release();
 	    reserved->instances = 0;
-	    IOLockUnlock(sAllClassesLock);
 	}
     }