diff --git a/README.md b/README.md
index 0b86d9e..e5c25be 100644
--- a/README.md
+++ b/README.md
@@ -22,7 +22,7 @@ composer and the Mailgun SDK.
 curl -sS https://getcomposer.org/installer | php
 
 # Add Mailgun as a dependency
-php composer.phar require mailgun/mailgun-php:~1.2
+php composer.phar require mailgun/mailgun-php:~1.3
 ``` 
 
 **For shared hosts without SSH access, check out our [Shared Host Instructions](SharedHostInstall.md).**
diff --git a/SharedHostInstall.md b/SharedHostInstall.md
index b0372a7..ab0d02f 100644
--- a/SharedHostInstall.md
+++ b/SharedHostInstall.md
@@ -11,7 +11,7 @@ Linux / Mac OSX:
 *PHP is typically installed by default, consult your distribution documentation. Instructions from [getcomposer.org](http://getcomposer.org/doc/00-intro.md#installation-nix).*  
 
 1. curl -sS https://getcomposer.org/installer | php  
-2. php composer.phar require mailgun/mailgun-php:~1.2  
+2. php composer.phar require mailgun/mailgun-php:~1.3  
 3. The files will be downloaded to your local computer.   
 4. Upload the files to your webserver.   
 
@@ -20,7 +20,7 @@ Windows:
 *PHP must be installed on your computer, [download](http://windows.php.net/download/0). Instructions from [getcomposer.org](http://getcomposer.org/doc/00-intro.md#installation-windows).* 
 
 1. Download and run [Composer-Setup.exe](https://getcomposer.org/Composer-Setup.exe).  
-2. Open a Command Prompt and type "php composer require mailgun/mailgun-php:~1.2".  
+2. Open a Command Prompt and type "php composer require mailgun/mailgun-php:~1.3".  
 3. The files will be downloaded to your local computer.   
 4. Upload the files to your webserver.   
 
diff --git a/composer.json b/composer.json
index 6a5c1aa..8eac3e3 100644
--- a/composer.json
+++ b/composer.json
@@ -2,7 +2,7 @@
     "name": "mailgun/mailgun-php",
     "description": "The Mailgun SDK provides methods for all API functions.",
     "require": {
-        "guzzle/guzzle": "3.7.1"
+        "guzzle/guzzle": "3.7.*"
     },
     "require-dev": {
         "phpunit/phpunit": "3.7.*"
diff --git a/src/Mailgun/Messages/MessageBuilder.php b/src/Mailgun/Messages/MessageBuilder.php
index 142da6f..8f96e2d 100644
--- a/src/Mailgun/Messages/MessageBuilder.php
+++ b/src/Mailgun/Messages/MessageBuilder.php
@@ -64,6 +64,9 @@ class MessageBuilder{
 		if(isset($this->message[$headerName])){
 			array_push($this->message[$headerName], $compiledAddress);
 		}
+		elseif($headerName == "h:reply-to"){
+			$this->message[$headerName] = $compiledAddress;
+		}
 		else{
 			$this->message[$headerName] = array($compiledAddress);
 		}
diff --git a/tests/Mailgun/Tests/Messages/MessageBuilderTest.php b/tests/Mailgun/Tests/Messages/MessageBuilderTest.php
index f8e3a2f..c73d4a6 100644
--- a/tests/Mailgun/Tests/Messages/MessageBuilderTest.php
+++ b/tests/Mailgun/Tests/Messages/MessageBuilderTest.php
@@ -38,6 +38,12 @@ class MessageBuilderTest extends \Mailgun\Tests\MailgunTestCase{
 		$messageObj = $message->getMessage();
 		$this->assertEquals(array("from" => array("'Test User' <test@samples.mailgun.org>")), $messageObj);
 	}
+	public function testSetReplyTo(){
+		$message = $this->client->MessageBuilder();
+		$message->setReplyToAddress("test@samples.mailgun.org", array("first" => "Test", "last" => "User"));
+		$messageObj = $message->getMessage();
+		$this->assertEquals(array("h:reply-to" => "'Test User' <test@samples.mailgun.org>"), $messageObj);
+	}
 	public function testSetSubject(){
 		$message = $this->client->MessageBuilder();
 		$message->setSubject("Test Subject");