diff --git a/setup.sh b/setup.sh
index 62114f6..aabc49d 100644
--- a/setup.sh
+++ b/setup.sh
@@ -14,7 +14,7 @@
 # License for the specific language governing permissions and limitations under
 # the License.
 
-set -e
+set -eu
 
 output(){
     printf '\e[1;34m%-6s\e[m\n' "${@}"