--- old/src/hotspot/share/gc/z/zPageAllocator.hpp	2018-01-16 19:52:47.906007570 +0900
+++ new/src/hotspot/share/gc/z/zPageAllocator.hpp	2018-01-16 19:52:47.758005013 +0900
@@ -36,6 +36,8 @@
 class ZPageAllocRequest;
 
 class ZPageAllocator VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
 private:
   ZLock                    _lock;
   ZVirtualMemoryManager    _virtual;