diff --git a/mod.js b/mod.js
index 35b9eaf..190a9b0 100644
--- a/mod.js
+++ b/mod.js
@@ -21,9 +21,13 @@ module.exports = ({
             'ak': apiKey
         }
     }));
+    /**
+     * @typedef tolgeeJson
+     * @type {Object.<string, Object.<string, string>>}
+     */
     /**
      * Download project i18n data as JSON objects
-     * @returns {Promise}
+     * @returns {Promise<tolgeeJson>}
      */
     const downloadJson = async () => {
         const
@@ -46,7 +50,7 @@ module.exports = ({
         downloadJson,
         /**
          *
-         * @param {object} json
+         * @param {tolgeeJson} json
          * @param {function} [onProgress]
          * @returns {Promise}
          */