--- old/src/hotspot/share/runtime/objectMonitor.hpp	2017-10-10 17:35:24.007254666 -0400
+++ new/src/hotspot/share/runtime/objectMonitor.hpp	2017-10-10 17:35:23.550500412 -0400
@@ -251,6 +251,7 @@
     ((ObjectMonitor::f ## _offset_in_bytes()) - markOopDesc::monitor_value)
 
   markOop   header() const;
+  markOopDesc* volatile* header_addr();
   void      set_header(markOop hdr);
 
   intptr_t is_busy() const {