--- old/src/hotspot/share/gc/shared/referencePolicy.hpp	2018-03-07 23:25:51.403528006 +0100
+++ new/src/hotspot/share/gc/shared/referencePolicy.hpp	2018-03-07 23:25:51.171520086 +0100
@@ -25,6 +25,8 @@
 #ifndef SHARE_VM_GC_SHARED_REFERENCEPOLICY_HPP
 #define SHARE_VM_GC_SHARED_REFERENCEPOLICY_HPP
 
+#include "oops/oopsHierarchy.hpp"
+
 // referencePolicy is used to determine when soft reference objects
 // should be cleared.