diff --git a/tools/xen/install_os_domU.sh b/tools/xen/install_os_domU.sh
index b49504d9e9..110bbd998c 100755
--- a/tools/xen/install_os_domU.sh
+++ b/tools/xen/install_os_domU.sh
@@ -10,6 +10,8 @@ set -o errexit
 set -o nounset
 set -o xtrace
 
+export LC_ALL=C
+
 # Abort if localrc is not set
 if [ ! -e ../../localrc ]; then
     echo "You must have a localrc with ALL necessary passwords defined before proceeding."