diff --git a/src/Defaults.php b/src/Defaults.php
index e62bed5..d442cbe 100644
--- a/src/Defaults.php
+++ b/src/Defaults.php
@@ -2,7 +2,7 @@
 namespace Ably;
 
 class Defaults {
-    const API_VERSION = '1.1';
+    const API_VERSION = '2.0';
     const LIB_VERSION = '1.1.9';
 
     static $restHost = "rest.ably.io";
diff --git a/src/Models/ClientOptions.php b/src/Models/ClientOptions.php
index ff2a688..5179178 100644
--- a/src/Models/ClientOptions.php
+++ b/src/Models/ClientOptions.php
@@ -104,7 +104,7 @@ class ClientOptions extends AuthOptions {
     /**
      * @var bool defaults to false for clients with version < 1.2, otherwise true
      */
-    public $idempotentRestPublishing = Defaults::API_VERSION >= '1.2';
+    public $idempotentRestPublishing = true
 
     /**
      * @var string a class that should be used for Auth