diff --git a/lib/apple.js b/lib/apple.js
index 5a8627e..e7c482e 100644
--- a/lib/apple.js
+++ b/lib/apple.js
@@ -41,10 +41,7 @@ var testMode = false;
 function isExpired(responseData) {
     if (responseData[REC_KEYS.LRI] && responseData[REC_KEYS.LRI][REC_KEYS.EXPIRES_DATE]) {
         var exp = parseInt(responseData[REC_KEYS.LRI][REC_KEYS.EXPIRES_DATE]);
-        if (exp > Date.now()) {
-            return true;
-        }
-        return false;
+        return exp > Date.now();
     }
     // old receipt
 }
@@ -349,7 +346,7 @@ module.exports.getPurchaseData = function (purchase, options) {
 };
 
 function bool(val) {
-    return val === 'true' ? true : false;
+    return val === 'true';
 }
 
 function getSubscriptionExpireDate(data) {
@@ -413,6 +410,8 @@ function send(url, content, cb) {
 
 function applyResponseData(target, source) {
     for (var key in source) {
+        if (!source.hasOwnProperty(key))
+            continue;
         if (target[key] === undefined) {
             target[key] = source[key];
         }