--- old/src/hotspot/share/gc/shared/collectedHeap.hpp	2018-02-16 14:08:05.689711223 +0100
+++ new/src/hotspot/share/gc/shared/collectedHeap.hpp	2018-02-16 14:08:05.537704684 +0100
@@ -492,7 +492,7 @@
   void pre_full_gc_dump(GCTimer* timer);
   void post_full_gc_dump(GCTimer* timer);
 
-  VirtualSpaceSummary create_heap_space_summary();
+  virtual VirtualSpaceSummary create_heap_space_summary();
   GCHeapSummary create_heap_summary();
 
   MetaspaceSummary create_metaspace_summary();