diff --git a/src/future/aws/PhutilAWSEC2Future.php b/src/future/aws/PhutilAWSEC2Future.php
index afa6109..b3eeef0 100644
--- a/src/future/aws/PhutilAWSEC2Future.php
+++ b/src/future/aws/PhutilAWSEC2Future.php
@@ -1,13 +1,12 @@
 <?php
 
 /**
  * @group aws
  */
 final class PhutilAWSEC2Future extends PhutilAWSFuture {
 
-  public function getHost() {
-    return 'ec2.us-west-1.amazonaws.com';
+  public function getServiceName() {
+    return 'ec2';
   }
 
 }
-
diff --git a/src/future/aws/PhutilAWSFuture.php b/src/future/aws/PhutilAWSFuture.php
index 49ec520..9f244c7 100644
--- a/src/future/aws/PhutilAWSFuture.php
+++ b/src/future/aws/PhutilAWSFuture.php
@@ -1,133 +1,144 @@
 <?php
 
 /**
  * @group aws
  */
 abstract class PhutilAWSFuture extends FutureProxy {
 
   private $future;
   private $awsAccessKey;
   private $awsPrivateKey;
+  private $awsRegion;
   private $builtRequest;
   private $params;
 
-  abstract public function getHost();
+  abstract public function getServiceName();
 
   public function __construct() {
     parent::__construct(null);
   }
 
   public function setAWSKeys($access, $private) {
     $this->awsAccessKey = $access;
     $this->awsPrivateKey = $private;
     return $this;
   }
 
   public function getAWSAccessKey() {
     return $this->awsAccessKey;
   }
 
   public function getAWSPrivateKey() {
     return $this->awsPrivateKey;
   }
 
+  public function getAWSRegion() {
+    return $this->awsRegion;
+  }
+
+  public function setAWSRegion($region) {
+    $this->awsRegion = $region;
+    return $this;
+  }
+
+  public function getHost() {
+    $host = $this->getServiceName().'.'.$this->awsRegion.'.amazonaws.com';
+    return $host;
+  }
+
   public function setRawAWSQuery($action, array $params = array()) {
     $this->params = $params;
     $this->params['Action'] = $action;
     return $this;
   }
 
-  public function getAWSKeys() {
-    return $this->AWSKeys;
-  }
-
   protected function getProxiedFuture() {
     if (!$this->future) {
       $params = $this->params;
 
       if (!$this->params) {
         throw new Exception("You must setRawAWSQuery()!");
       }
 
       if (!$this->getAWSAccessKey()) {
         throw new Exception("You must setAWSKeys()!");
       }
 
       $params['AWSAccessKeyId'] = $this->getAWSAccessKey();
       $params['Version']        = '2011-12-15';
       $params['Timestamp']      = date('c');
 
       $params = $this->sign($params);
 
       $uri = new PhutilURI('http://'.$this->getHost().'/');
       $uri->setQueryParams($params);
 
       $this->future = new HTTPFuture($uri);
     }
 
     return $this->future;
   }
 
   protected function didReceiveResult($result) {
     list($status, $body, $headers) = $result;
 
     try {
       $xml = @(new SimpleXMLElement($body));
     } catch (Exception $ex) {
       $xml = null;
     }
 
     if ($status->isError() || !$xml) {
       if (!($status instanceof HTTPFutureResponseStatusHTTP)) {
         throw $status;
       }
 
       $params = array(
         'body' => $body,
       );
       if ($xml) {
         $params['RequestID'] = $xml->RequestID[0];
         foreach ($xml->Errors[0] as $error) {
           $params['Errors'][] = array($error->Code, $error->Message);
         }
       }
 
       throw new PhutilAWSException($status->getStatusCode(), $params);
     }
 
     return $xml;
   }
 
   /**
    * http://bit.ly/wU0JFh
    */
   private function sign(array $params) {
 
     $params['SignatureMethod'] = 'HmacSHA256';
     $params['SignatureVersion'] = '2';
 
     ksort($params);
 
     $pstr = array();
     foreach ($params as $key => $value) {
       $pstr[] = rawurlencode($key).'='.rawurlencode($value);
     }
     $pstr = implode('&', $pstr);
 
     $sign = "GET"."\n".
             strtolower($this->getHost())."\n".
             "/"."\n".
             $pstr;
 
     $hash = hash_hmac(
       'sha256',
       $sign,
       $this->getAWSPrivateKey(),
       $raw_ouput = true);
 
     $params['Signature'] = base64_encode($hash);
 
     return $params;
   }
 
 }