diff --git a/tools/xen/install_os_domU.sh b/tools/xen/install_os_domU.sh
index 352f63acce..19453c1233 100755
--- a/tools/xen/install_os_domU.sh
+++ b/tools/xen/install_os_domU.sh
@@ -57,8 +57,9 @@ then
 fi
 
 # get nova
-wget https://github.com/openstack/nova/zipball/master --no-check-certificate
-unzip -o master -d ./nova
+nova_zipball=$(echo $NOVA_REPO | sed "s:\.git$::;s:$:/zipball/$NOVA_BRANCH:g")
+wget $nova_zipball -O nova-zipball --no-check-certificate
+unzip -o nova-zipball  -d ./nova
 
 # install xapi plugins
 XAPI_PLUGIN_DIR=/etc/xapi.d/plugins/