diff --git a/lib/core.js b/lib/core.js
index 93d73b6..a6ec745 100644
--- a/lib/core.js
+++ b/lib/core.js
@@ -1,16 +1,8 @@
 'use strict';
 
-var LE = require('../');
-var ipc = {}; // in-process cache
-
-module.exports.create = function (defaults, handlers, backend) {
-  var backendDefaults = backend.getDefaults && backend.getDefaults || backend.defaults || {};
-
-  defaults.server = defaults.server || LE.liveServer;
-  handlers.merge = require('./common').merge;
-  handlers.tplCopy = require('./common').tplCopy;
-
+module.exports.create = function (le) {
   var PromiseA = require('bluebird');
+  var utils = require('./utils'); // merge, tplCopy;
   var RSA = PromiseA.promisifyAll(require('rsa-compat').RSA);
   var LeCore = PromiseA.promisifyAll(require('letiny-core'));
   var crypto = require('crypto');
@@ -28,8 +20,6 @@ module.exports.create = function (defaults, handlers, backend) {
   }
 
   function createAccount(args, handlers) {
-    args.rsaKeySize = args.rsaKeySize || 2048;
-
     return RSA.generateKeypairAsync(args.rsaKeySize, 65537, { public: true, pem: true }).then(function (keypair) {
 
       return LeCore.registerNewAccountAsync({
@@ -73,21 +63,19 @@ module.exports.create = function (defaults, handlers, backend) {
     var now = Date.now();
 
     // TODO check response header on request for cache time
-    if ((now - ipc.acmeUrlsUpdatedAt) < 10 * 60 * 1000) {
-      return PromiseA.resolve(ipc.acmeUrls);
+    if ((now - le._ipc.acmeUrlsUpdatedAt) < 10 * 60 * 1000) {
+      return PromiseA.resolve(le._ipc.acmeUrls);
     }
 
     return LeCore.getAcmeUrlsAsync(args.server).then(function (data) {
-      ipc.acmeUrlsUpdatedAt = Date.now();
-      ipc.acmeUrls = data;
+      le._ipc.acmeUrlsUpdatedAt = Date.now();
+      le._ipc.acmeUrls = data;
 
-      return ipc.acmeUrls;
+      return le._ipc.acmeUrls;
     });
   }
 
   function getCertificateAsync(args, defaults, handlers) {
-    args.rsaKeySize = args.rsaKeySize || 2048;
-    args.challengeType = args.challengeType || 'http-01';
 
     function log() {
       if (args.debug || defaults.debug) {
@@ -223,7 +211,6 @@ module.exports.create = function (defaults, handlers, backend) {
 
   var wrapped = {
     registerAsync: function (args) {
-      var utils = require('./lib/common');
       var err;
 
       if (!Array.isArray(args.domains)) {
diff --git a/lib/common.js b/lib/utils.js
similarity index 100%
rename from lib/common.js
rename to lib/utils.js