diff --git a/README.md b/README.md
index 0f46cfc..d07e4ed 100644
--- a/README.md
+++ b/README.md
@@ -17,8 +17,7 @@ Require the Clockwork library:
 	require 'class-Clockwork.php';
 
 ### Sending a message
-
-    $clockwork = new Clockwork( $API_KEY );
+    $clockwork = new \Clockwork\Clockwork( $API_KEY );
     $message = array( 'to' => '441234567891', 'message' => 'This is a test!' );
     $result = $clockwork->send( $message );
 
@@ -26,7 +25,7 @@ Require the Clockwork library:
 
 We recommend you use batch sizes of 500 messages or fewer. By limiting the batch size it prevents any timeouts when sending.
 
-    $clockwork = new Clockwork( $API_KEY );
+    $clockwork = new \Clockwork\Clockwork( $API_KEY );
     $messages = array( 
       array( 'to' => '441234567891', 'message' => 'This is a test!' ),
       array( 'to' => '441234567892', 'message' => 'This is a test 2!' )
@@ -103,7 +102,7 @@ For example, if you send to invalid phone number "abc":
 
 Check your available SMS balance:
 
-    $clockwork = new Clockwork( $API_KEY );
+    $clockwork = new \Clockwork\Clockwork( $API_KEY );
     $clockwork->checkBalance();
     
 This will return:
@@ -121,11 +120,11 @@ The Clockwork wrapper will throw a `ClockworkException` if the entire call faile
 
     try 
     {
-      $clockwork = new Clockwork( 'invalid_key' );
+      $clockwork = new \Clockwork\Clockwork( 'invalid_key' );
       $message = array( 'to' => 'abc', 'message' => 'This is a test!' );
       $result = $clockwork->send( $message );
     }
-    catch( ClockworkException $e )
+    catch( \Clockwork\ClockworkException $e )
     {
       print $e->getMessage();
       // Invalid API Key
@@ -183,7 +182,7 @@ Set option values individually on each message.
 
 In this example, one message will be from Clockwork and the other from 84433:
 
-    $clockwork = new Clockwork( $API_KEY, $options );
+    $clockwork = new \Clockwork\Clockwork( $API_KEY, $options );
     $messages = array( 
       array( 'to' => '441234567891', 'message' => 'This is a test!', 'from' => 'Clockwork' ),
       array( 'to' => '441234567892', 'message' => 'This is a test 2!', 'from' => '84433' )
@@ -207,7 +206,7 @@ If you're seeing this error there are two fixes available, the first is easy, si
 #### Disable SSL on Clockwork calls
 
     $options = array( 'ssl' => false );
-    $clockwork = new Clockwork( $API_KEY, $options );
+    $clockwork = new \Clockwork\Clockwork( $API_KEY, $options );
 
 #### Setup SSL root certificates on your server
 
diff --git a/composer.json b/composer.json
new file mode 100644
index 0000000..50c9208
--- /dev/null
+++ b/composer.json
@@ -0,0 +1,12 @@
+{
+    "name": "weemen/clockwork-php",
+    "minimum-stability":"dev",
+    "require-dev": {
+        "phpunit/phpunit": "3.7.*"
+    },
+    "autoload": {
+        "psr-0": {
+            "Clockwork\\": "src/"
+        }
+    }
+}
\ No newline at end of file
diff --git a/class-Clockwork.php b/src/Clockwork/Clockwork.php
similarity index 94%
rename from class-Clockwork.php
rename to src/Clockwork/Clockwork.php
index b38b886..2bfcfa3 100755
--- a/class-Clockwork.php
+++ b/src/Clockwork/Clockwork.php
@@ -9,9 +9,8 @@
 * @version     1.3.0
 */
 
-if ( !class_exists('ClockworkException') ) {
-  require_once('class-ClockworkException.php');
-}
+namespace Clockwork;
+use ClockworkException;
 
 /**
 * Main Clockwork API Class
@@ -173,7 +172,7 @@ public function send(array $sms) {
       $sms = array($sms);
     }
 
-    $req_doc = new DOMDocument('1.0', 'UTF-8');
+    $req_doc = new \DOMDocument('1.0', 'UTF-8');
     $root = $req_doc->createElement('Message');
     $req_doc->appendChild($root);
 
@@ -251,7 +250,7 @@ public function send(array $sms) {
     $req_xml = $req_doc->saveXML();
      
     $resp_xml = $this->postToClockwork(self::API_SMS_METHOD, $req_xml);
-    $resp_doc = new DOMDocument();
+    $resp_doc = new \DOMDocument();
     $resp_doc->loadXML($resp_xml);   
 
     $response = array();
@@ -317,7 +316,7 @@ public function send(array $sms) {
   */
   public function checkCredit() {
     // Create XML doc for request
-    $req_doc = new DOMDocument('1.0', 'UTF-8');
+    $req_doc = new \DOMDocument('1.0', 'UTF-8');
     $root = $req_doc->createElement('Credit');
     $req_doc->appendChild($root);
     $root->appendChild($req_doc->createElement('Key', $this->key));
@@ -327,7 +326,7 @@ public function checkCredit() {
     $resp_xml = $this->postToClockwork(self::API_CREDIT_METHOD, $req_xml);
 
     // Create XML doc for response
-    $resp_doc = new DOMDocument();
+    $resp_doc = new \DOMDocument();
     $resp_doc->loadXML($resp_xml);
 
     // Parse the response to find credit value
@@ -365,7 +364,7 @@ public function checkCredit() {
   */
   public function checkBalance() {
     // Create XML doc for request
-    $req_doc = new DOMDocument('1.0', 'UTF-8');
+    $req_doc = new \DOMDocument('1.0', 'UTF-8');
     $root = $req_doc->createElement('Balance');
     $req_doc->appendChild($root);
     $root->appendChild($req_doc->createElement('Key', $this->key));
@@ -375,7 +374,7 @@ public function checkBalance() {
     $resp_xml = $this->postToClockwork(self::API_BALANCE_METHOD, $req_xml);
 
     // Create XML doc for response
-    $resp_doc = new DOMDocument();
+    $resp_doc = new \DOMDocument();
     $resp_doc->loadXML($resp_xml);
     
     // Parse the response to find balance value
@@ -426,7 +425,7 @@ public function checkBalance() {
   */
   public function checkKey() {
     // Create XML doc for request
-    $req_doc = new DOMDocument('1.0', 'UTF-8');
+    $req_doc = new \DOMDocument('1.0', 'UTF-8');
     $root = $req_doc->createElement('Authenticate');
     $req_doc->appendChild($root);
     $root->appendChild($req_doc->createElement('Key', $this->key));
@@ -436,7 +435,7 @@ public function checkKey() {
     $resp_xml = $this->postToClockwork(self::API_AUTH_METHOD, $req_xml);
 
     // Create XML doc for response
-    $resp_doc = new DOMDocument();
+    $resp_doc = new \DOMDocument();
     $resp_doc->loadXML($resp_xml);
         
     // Parse the response to see if authenticated
@@ -525,9 +524,9 @@ protected function xmlPost($url, $data) {
       $info = curl_getinfo($ch);
 
       if ($response === false || $info['http_code'] != 200) {
-        throw new Exception('HTTP Error calling Clockwork API - HTTP Status: ' . $info['http_code'] . ' - cURL Erorr: ' . curl_error($ch));
+        throw new \Exception('HTTP Error calling Clockwork API - HTTP Status: ' . $info['http_code'] . ' - cURL Erorr: ' . curl_error($ch));
       } elseif (curl_errno($ch) > 0) {
-        throw new Exception('HTTP Error calling Clockwork API - cURL Error: ' . curl_error($ch));
+        throw new \Exception('HTTP Error calling Clockwork API - cURL Error: ' . curl_error($ch));
       }
 
       curl_close($ch);
@@ -553,17 +552,17 @@ protected function xmlPost($url, $data) {
       $fp = @fopen($url, 'rb', false, $ctx);
       if (!$fp) {
         ini_set('track_errors',$track);
-        throw new Exception("HTTP Error calling Clockwork API - fopen Error: $php_errormsg");
+        throw new \Exception("HTTP Error calling Clockwork API - fopen Error: $php_errormsg");
       }
       $response = @stream_get_contents($fp);
       if ($response === false) {
         ini_set('track_errors',$track);
-        throw new Exception("HTTP Error calling Clockwork API - stream Error: $php_errormsg");
+        throw new \Exception("HTTP Error calling Clockwork API - stream Error: $php_errormsg");
       }
       ini_set('track_errors',$track);
       return $response;
     } else {
-      throw new Exception("Clockwork requires PHP5 with cURL or HTTP stream support");
+      throw new \Exception("Clockwork requires PHP5 with cURL or HTTP stream support");
     }
   }
 
diff --git a/class-ClockworkException.php b/src/Clockwork/ClockworkException.php
similarity index 95%
rename from class-ClockworkException.php
rename to src/Clockwork/ClockworkException.php
index bf8d63e..51680ff 100755
--- a/class-ClockworkException.php
+++ b/src/Clockwork/ClockworkException.php
@@ -6,7 +6,9 @@
  * @copyright   Mediaburst Ltd 2012
  * @license     ISC
  * @link        http://www.clockworksms.com
- */ 
+ */
+
+namespace Clockwork;
 
 /*
  * ClockworkException
diff --git a/tests/Clockwork/ClockworkTest.php b/tests/Clockwork/ClockworkTest.php
new file mode 100644
index 0000000..b1e4e90
--- /dev/null
+++ b/tests/Clockwork/ClockworkTest.php
@@ -0,0 +1,26 @@
+<?php
+
+namespace Clockwork;
+use \PHPUnit_Framework_TestCase;
+
+class ClockworkTest extends PHPUnit_Framework_TestCase {
+
+    public function msisdProvider()
+    {
+        return array(
+          array('01234567', 0), //starts with 0
+          array('11234567', 1),
+          array('1123456', 0),  //not enough numbers
+          array('1123456789000', 1),
+          array('11234567890000', 0) //too many numbers
+        );
+    }
+
+    /**
+     * @dataProvider msisdProvider
+     */
+    public function testIsValidMsisd($number, $expectedResult)
+    {
+        $this->assertEquals($expectedResult,Clockwork::is_valid_msisdn($number));
+    }
+} 
\ No newline at end of file
diff --git a/tests/bootstrap.php b/tests/bootstrap.php
new file mode 100644
index 0000000..5bfc905
--- /dev/null
+++ b/tests/bootstrap.php
@@ -0,0 +1,2 @@
+<?php
+require 'vendor/autoload.php';
\ No newline at end of file