--- old/src/hotspot/cpu/zero/globals_zero.hpp	2020-02-03 17:41:56.000000000 -0500
+++ new/src/hotspot/cpu/zero/globals_zero.hpp	2020-02-03 17:41:55.000000000 -0500
@@ -73,6 +73,10 @@
 // No performance work done here yet.
 define_pd_global(bool, CompactStrings, false);
 
+// No ObjectMonitor C2 fast_lock() or fast_unlock() so no need to
+// use a handshake for safety.
+define_pd_global(bool, HandshakeAfterDeflateIdleMonitors, false);
+
 #define ARCH_FLAGS(develop, \
                    product, \
                    diagnostic, \