--- a/src/hotspot/cpu/s390/globals_s390.hpp	Thu Nov 09 12:43:13 2017 -0800
+++ b/src/hotspot/cpu/s390/globals_s390.hpp	Fri Nov 10 09:16:42 2017 +0100
@@ -71,7 +71,7 @@
 define_pd_global(bool, RewriteBytecodes,     true);
 define_pd_global(bool, RewriteFrequentPairs, true);
 
-define_pd_global(bool, UseMembar,            false);
+define_pd_global(bool, UseMembar,            true);
 
 define_pd_global(bool, PreserveFramePointer, false);