diff --git a/standalone/windows/build.sh b/standalone/windows/build.sh
index 6ba9c58101..bd7b1b665d 100755
--- a/standalone/windows/build.sh
+++ b/standalone/windows/build.sh
@@ -22,6 +22,7 @@ withcygpreferred () {
 
 # This tells git-annex where to upgrade itself from.
 UPGRADE_LOCATION=http://downloads.kitenet.net/git-annex/windows/current/git-annex-installer.exe
+export UPGRADE_LOCATION
 
 # This can be used to force git-annex to build supporting a particular
 # version of git, instead of the version installed at build time.