diff --git a/dom0.sh b/dom0.sh
index 7d39042..539dcbf 100644
--- a/dom0.sh
+++ b/dom0.sh
@@ -14,7 +14,7 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
-set -e
+set -eu
 
 # Enabling discard and fstrim
 sudo sed -i 's/issue_discards = 0/issue_discards = 1/g' /etc/lvm/lvm.conf