--- old/src/hotspot/share/c1/c1_Runtime1.cpp	2019-08-23 20:45:59.376526584 +0000
+++ new/src/hotspot/share/c1/c1_Runtime1.cpp	2019-08-23 20:45:58.371503386 +0000
@@ -705,6 +705,9 @@
     Atomic::inc(BiasedLocking::slow_path_entry_count_addr());
   }
   Handle h_obj(thread, obj);
+  if (!UseFastLocking) {
+    lock->set_obj(obj);
+  }
   assert(obj == lock->obj(), "must match");
   ObjectSynchronizer::enter(h_obj, lock->lock(), THREAD);
 JRT_END