--- xnu/xnu-201.5/libkern/c++/OSUnserialize.cpp
+++ xnu/xnu-123.5/libkern/c++/OSUnserialize.cpp
@@ -1567,9 +1567,9 @@
 
 	if (!lock) {
 		lock = mutex_alloc(ETAP_IO_AHA);
-		mutex_lock(lock);
+		_mutex_lock(lock);
 	} else {
-		mutex_lock(lock);
+		_mutex_lock(lock);
 
 	}