diff --git a/validate_workflow.sh b/validate_workflow.sh
index 0ef7e19d6d4b45fcf9818c8fe4af5ab5a38df484..42ca7930c896665d435e5b027c34b2dc11e914a6 100755
--- a/validate_workflow.sh
+++ b/validate_workflow.sh
@@ -176,7 +176,7 @@ get_cli_args() {
                 WITH_PIPE=1
                 shift
                 ;;
-            -d | --debug)
+            -D | --debug)
                 WITH_DEBUG=1
                 shift
                 ;;
@@ -186,12 +186,16 @@ get_cli_args() {
                 ;;
         esac
     done
-    if [ "$FILES_MODE" != "sort" -a  "$FILES_MODE" != "delete" -a "$FILES_MODE" != "nothing" ]; then
+    if [ "$FILES_MODE" != "sort" ] && [ "$FILES_MODE" != "delete" ] && [ "$FILES_MODE" != "nothing" ]; then
         error "param --files-mode must be 'sort', 'delete' or 'nothing'!"
         exit 1
     fi
-    if [ "$MODE" != "auto" -a  "$MODE" != "mediathek" -a "$MODE" != "fotothek" \
-        -a  "$MODE" != "save" -a  "$MODE" != "kitodo" -a  "$MODE" != "lfulg" ]; then
+    if [ "$MODE" != "auto" ] \
+        && [ "$MODE" != "mediathek" ] \
+        && [ "$MODE" != "fotothek" ] \
+        && [ "$MODE" != "save" ] \
+        && [ "$MODE" != "kitodo" ] \
+        && [ "$MODE" != "lfulg" ]; then
         error "param --mode must be 'auto', 'mediathek', 'fotothek', 'save', 'kitodo' or 'lfulg'!"
         exit 1
     fi