diff -r cbe83e9c2100 -r f1bb77833b59 src/hotspot/share/runtime/arguments.cpp
--- a/src/hotspot/share/runtime/arguments.cpp	Thu Nov 08 11:22:28 2018 -0800
+++ b/src/hotspot/share/runtime/arguments.cpp	Thu Nov 08 11:45:13 2018 -0800
@@ -532,7 +532,7 @@
   { "MaxRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
   { "MinRAMFraction",               JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
   { "InitialRAMFraction",           JDK_Version::jdk(10),  JDK_Version::undefined(), JDK_Version::undefined() },
-  { "UseMembar",                    JDK_Version::jdk(10), JDK_Version::undefined(), JDK_Version::undefined() },
+  { "UseMembar",                    JDK_Version::jdk(10), JDK_Version::jdk(12), JDK_Version::undefined() },
   { "CompilerThreadHintNoPreempt",  JDK_Version::jdk(11), JDK_Version::jdk(12), JDK_Version::jdk(13) },
   { "VMThreadHintNoPreempt",        JDK_Version::jdk(11), JDK_Version::jdk(12), JDK_Version::jdk(13) },