--- a/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Mon Dec 01 12:11:11 2014 +0100
+++ b/hotspot/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp	Tue Dec 02 09:51:16 2014 +0100
@@ -721,7 +721,8 @@
 
  private:
   // Support for parallelizing young gen rescan in CMS remark phase
-  Generation* _young_gen;  // the younger gen
+  ParNewGeneration* _young_gen;  // the younger gen
+
   HeapWord** _top_addr;    // ... Top of Eden
   HeapWord** _end_addr;    // ... End of Eden
   Mutex*     _eden_chunk_lock;