--- old/src/hotspot/share/opto/graphKit.cpp	2019-07-04 11:52:51.000000000 +0200
+++ new/src/hotspot/share/opto/graphKit.cpp	2019-07-04 11:52:46.000000000 +0200
@@ -3591,12 +3591,6 @@
   if( !GenerateSynchronizationCode )
     return NULL;                // Not locking things?
 
-  // We cannot lock on a value type
-  const TypeOopPtr* objptr = _gvn.type(obj)->make_oopptr();
-  if (objptr->can_be_value_type()) {
-    gen_value_type_guard(obj, 1);
-  }
-
   if (stopped())                // Dead monitor?
     return NULL;