diff --git a/dokku b/dokku
index 3b4a7c26a..39d6d9781 100755
--- a/dokku
+++ b/dokku
@@ -177,17 +177,17 @@ EOF
     implemented=0
     for script in $PLUGIN_PATH/*/commands; do
       set +e; $script "$@" ; exit_code=$? ; set -e
-      if [ "$exit_code" -eq "$DOKKU_NOT_IMPLEMENTED_EXIT" ]; then
+      if [[ "$exit_code" -eq "$DOKKU_NOT_IMPLEMENTED_EXIT" ]]; then
         continue
       fi
 
       implemented=1
-      if [ "$exit_code" -ne "$DOKKU_VALID_EXIT" ]; then
+      if [[ "$exit_code" -ne "$DOKKU_VALID_EXIT" ]]; then
         exit $exit_code
       fi
     done
 
-    if [ "$implemented" -eq 0 ]; then
+    if [[ "$implemented" -eq 0 ]]; then
       dokku_log_warn "\`$*\` is not a dokku command."
       dokku_log_warn "See \`dokku help\` for a list of available commands."
       exit 1
diff --git a/plugins/docker-options/commands b/plugins/docker-options/commands
index d2cc8b496..46bc8a8c0 100755
--- a/plugins/docker-options/commands
+++ b/plugins/docker-options/commands
@@ -146,4 +146,8 @@ case "$1" in
 EOF
   ;;
 
+  *)
+    exit $DOKKU_NOT_IMPLEMENTED_EXIT
+  ;;
+
 esac