diff -r 3dbd3cdfe0d6 -r c68a1df5c79a contrib/packaging/wix/defines.wxi
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/contrib/packaging/wix/defines.wxi	Thu Mar 07 15:37:42 2019 -0800
@@ -0,0 +1,9 @@
+<Include>
+
+  <?if $(var.Platform) = "x64" ?>
+    <?define IsX64 = yes ?>
+  <?else?>
+    <?define IsX64 = no ?>
+  <?endif?>
+
+</Include>