diff --git a/lib/cartodb/middleware/clean-up-query-params.js b/lib/cartodb/middleware/clean-up-query-params.js
index 2553380d..d5c93c07 100644
--- a/lib/cartodb/middleware/clean-up-query-params.js
+++ b/lib/cartodb/middleware/clean-up-query-params.js
@@ -20,11 +20,7 @@ module.exports = function cleanUpQueryParamsMiddleware (customQueryParams = [])
     }
 
     return function cleanUpQueryParams (req, res, next) {
-        var allowedQueryParams = REQUEST_QUERY_PARAMS_WHITELIST;
-
-        if (Array.isArray(customQueryParams)) {
-            allowedQueryParams = allowedQueryParams.concat(customQueryParams);
-        }
+        const allowedQueryParams = [...REQUEST_QUERY_PARAMS_WHITELIST, ...customQueryParams];
 
         req.query = _.pick(req.query, allowedQueryParams);