--- a/src/hotspot/share/gc/shared/blockOffsetTable.hpp	Fri Jan 04 20:58:35 2019 +0100
+++ b/src/hotspot/share/gc/shared/blockOffsetTable.hpp	Fri Jan 04 15:06:01 2019 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -265,6 +265,8 @@
   HeapWord* address_for_index(size_t index) const;
 };
 
+class Space;
+
 //////////////////////////////////////////////////////////////////////////
 // The BlockOffsetArray whose subtypes use the BlockOffsetSharedArray.
 //////////////////////////////////////////////////////////////////////////