--- old/src/share/vm/gc/g1/g1YoungGenSizer.cpp	2016-07-12 12:11:12.000000000 +0200
+++ new/src/share/vm/gc/g1/g1YoungGenSizer.cpp	2016-07-12 12:11:12.000000000 +0200
@@ -45,7 +45,7 @@
                             "A new max generation size of " SIZE_FORMAT "k will be used.",
                             NewSize/K, MaxNewSize/K, NewSize/K);
     }
-    MaxNewSize = NewSize;
+    FLAG_SET_ERGO(size_t, MaxNewSize, NewSize);
   }
 
   if (FLAG_IS_CMDLINE(NewSize)) {