--- old/src/hotspot/share/gc/g1/g1Arguments.hpp	2018-02-20 23:17:40.432608119 +0100
+++ new/src/hotspot/share/gc/g1/g1Arguments.hpp	2018-02-20 23:17:40.208600462 +0100
@@ -25,11 +25,13 @@
 #ifndef SHARE_GC_G1_G1ARGUMENTS_HPP
 #define SHARE_GC_G1_G1ARGUMENTS_HPP
 
+#include "gc/g1/g1Settings.hpp"
 #include "gc/shared/gcArguments.hpp"
 
-class CollectedHeap;
-
 class G1Arguments : public GCArguments {
+private:
+  G1Settings initialize_heap_flags();
+
 public:
   virtual void initialize_flags();
   virtual bool parse_verification_type(const char* type);