--- old/src/share/vm/classfile/moduleEntry.cpp	2016-09-07 10:22:17.985902539 -0400
+++ new/src/share/vm/classfile/moduleEntry.cpp	2016-09-07 10:22:16.508884933 -0400
@@ -92,7 +92,7 @@
   // read java.base.  If either of these conditions
   // hold, readability has been established.
   if (!this->is_named() ||
-      (m == ModuleEntryTable::javabase_module())) {
+      (m == ModuleEntryTable::javabase_moduleEntry())) {
     return true;
   }
 
@@ -358,16 +358,23 @@
   }
 
   // Set java.lang.reflect.Module, version and location for java.base
-  ModuleEntry* jb_module = javabase_module();
+  ModuleEntry* jb_module = javabase_moduleEntry();
   assert(jb_module != NULL, "java.base ModuleEntry not defined");
-  jb_module->set_module(boot_loader_data->add_handle(module_handle));
   jb_module->set_version(version);
   jb_module->set_location(location);
+  // Once java.base's ModuleEntry _module field is set with the known
+  // java.lang.reflect.Module, java.base is considered "defined" to the VM.
+  jb_module->set_module_release_store(boot_loader_data->add_handle(module_handle));
+
   // Store pointer to the ModuleEntry for java.base in the java.lang.reflect.Module object.
   java_lang_reflect_Module::set_module_entry(module_handle(), jb_module);
+
+  // Patch any previously loaded classes' module field with java.base's java.lang.reflect.Module.
+  patch_javabase_entries(module_handle);
 }
 
 void ModuleEntryTable::patch_javabase_entries(Handle module_handle) {
+  assert(Module_lock->owned_by_self(), "should have the Module_lock");
   if (module_handle.is_null()) {
     fatal("Unable to patch the module field of classes loaded prior to java.base's definition, invalid java.lang.reflect.Module");
   }