diff --git a/lib/sandbox.js b/lib/sandbox.js
index 7b30f42..e0c52a4 100644
--- a/lib/sandbox.js
+++ b/lib/sandbox.js
@@ -935,6 +935,11 @@ module.exports.cli = {
                     return;
                 }
 
+                // set as empty array, in case the original list came undefined
+                if ( typeof list !== 'object' ) {
+                    list = [];
+                }
+
                 if (sortBy) {
                     list = require('./json').sort(list, sortBy);
                 }