diff -r b398685dd029 -r f51714d3385d make/autoconf/hotspot.m4
--- a/make/autoconf/hotspot.m4	Tue Nov 12 09:25:39 2019 +0000
+++ b/make/autoconf/hotspot.m4	Tue Nov 12 09:27:21 2019 +0000
@@ -1,5 +1,5 @@
 #
-# Copyright (c) 2011, 2018, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 2011, 2019, Oracle and/or its affiliates. All rights reserved.
 # DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 #
 # This code is free software; you can redistribute it and/or modify it
@@ -351,7 +351,8 @@
   # Only enable ZGC on supported platforms
   AC_MSG_CHECKING([if zgc can be built])
   if (test "x$OPENJDK_TARGET_OS" = "xlinux" && test "x$OPENJDK_TARGET_CPU" = "xx86_64") || \
-     (test "x$OPENJDK_TARGET_OS" = "xlinux" && test "x$OPENJDK_TARGET_CPU" = "xaarch64"); then
+     (test "x$OPENJDK_TARGET_OS" = "xlinux" && test "x$OPENJDK_TARGET_CPU" = "xaarch64") ||
+     (test "x$OPENJDK_TARGET_OS" = "xmacosx" && test "x$OPENJDK_TARGET_CPU" = "xx86_64"); then
     AC_MSG_RESULT([yes])
   else
     DISABLED_JVM_FEATURES="$DISABLED_JVM_FEATURES zgc"