diff --git a/lib/services/dwh-api/dwh-api-service.js b/lib/services/dwh-api/dwh-api-service.js
index 014e582..7e7f6c2 100644
--- a/lib/services/dwh-api/dwh-api-service.js
+++ b/lib/services/dwh-api/dwh-api-service.js
@@ -71,7 +71,7 @@ module.exports = class DwhApiService {
                 const queryMethod = `query${actionKey}${methodKey}`;
                 
                 this.debug('setup %s for %s', queryMethod, m);
-                this[queryMethod] = function(token, data, suffix, transformFn, transformErr) {
+                this[queryMethod] = (token, data, suffix, transformFn, transformErr) => {
                     return this.query(token, data, action, m, suffix, transformFn, transformErr);
                 };
                 this._methods[m] = this[queryMethod];