--- old/src/hotspot/share/gc/g1/g1Arguments.cpp	2018-04-27 15:29:23.678203618 +0200
+++ new/src/hotspot/share/gc/g1/g1Arguments.cpp	2018-04-27 15:29:23.430203627 +0200
@@ -81,11 +81,9 @@
     vm_exit_during_initialization("The flag -XX:+UseG1GC can not be combined with -XX:ParallelGCThreads=0", NULL);
   }
 
-#if INCLUDE_ALL_GCS
   if (FLAG_IS_DEFAULT(G1ConcRefinementThreads)) {
     FLAG_SET_ERGO(uint, G1ConcRefinementThreads, ParallelGCThreads);
   }
-#endif
 
   // MarkStackSize will be set (if it hasn't been set by the user)
   // when concurrent marking is initialized.