--- old/make/autoconf/hotspot.m4	2019-10-31 09:39:40.648976519 +0100
+++ new/make/autoconf/hotspot.m4	2019-10-31 09:39:40.200969353 +0100
@@ -351,6 +351,7 @@
   # 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$OPENJDK_TARGET_OS" = "xwindows" && test "x$OPENJDK_TARGET_CPU" = "xx86_64") || \
      (test "x$OPENJDK_TARGET_OS" = "xlinux" && test "x$OPENJDK_TARGET_CPU" = "xaarch64"); then
     AC_MSG_RESULT([yes])
   else