diff --git a/index.js b/index.js
index 0a615c8..da439d1 100644
--- a/index.js
+++ b/index.js
@@ -11,7 +11,7 @@ var util = require('util');
 function promisifyAll(obj) {
   var aobj = {};
   Object.keys(obj).forEach(function (key) {
-    aobj[key] = util.promisify(obj[key]);
+    aobj[key + 'Async'] = util.promisify(obj[key]);
   });
   return aobj;
 }
diff --git a/package.json b/package.json
index a94efe0..17a9a4c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "le-store-certbot",
-  "version": "2.1.5",
+  "version": "2.1.6",
   "description": "The \"certbot\" storage strategy for Greenlock.js",
   "main": "index.js",
   "scripts": {