diff --git a/_build/update_site.sh b/_build/update_site.sh
index 09745740..f5ada4cc 100755
--- a/_build/update_site.sh
+++ b/_build/update_site.sh
@@ -62,6 +62,7 @@ case "${1:-nil}" in
     echo
     echo "auto: only builds if the latest commit is GPG signed by an authorized key"
     echo "force: builds latest commit no matter what"
+    exit 1
   ;;
 esac