diff --git a/advagg.module b/advagg.module
index 79108f4..282c94f 100644
--- a/advagg.module
+++ b/advagg.module
@@ -442,6 +442,9 @@ function advagg_processor(&$variables) {
     }
   }
 
+  // Send requests to server if async enabled.
+  advagg_async_send_http_request();
+
   // Write debug info to watchdog if debugging enabled.
   if (variable_get('advagg_debug', ADVAGG_DEBUG)) {
     $data = array(
@@ -1965,10 +1968,15 @@ function advagg_css_js_file_builder($type, $files, $counter = '', $force = FALSE
           'Host' => $_SERVER['HTTP_HOST'],
         );
 
-        // Set timeout.
-        $socket_timeout = ini_set('default_socket_timeout', variable_get('advagg_socket_timeout', ADVAGG_SOCKET_TIMEOUT));
-        drupal_http_request($url, $headers, 'GET');
-        ini_set('default_socket_timeout', $socket_timeout);
+        if (function_exists('stream_socket_client')) {
+          advagg_async_connect_http_request($url, array('headers' => $headers));
+        }
+        else {
+          // Set timeout.
+          $socket_timeout = ini_set('default_socket_timeout', variable_get('advagg_socket_timeout', ADVAGG_SOCKET_TIMEOUT));
+          drupal_http_request($url, $headers, 'GET');
+          ini_set('default_socket_timeout', $socket_timeout);
+        }
 
         // Return filepath.
         $output[$filepath] = array('prefix' => $prefix, 'suffix' => $suffix);
@@ -2466,3 +2474,234 @@ function _advagg_drupal_load_stylesheet($matches) {
   // that will be done later.
   return preg_replace('/url\(\s*([\'"]?)(?![a-z]+:|\/+)/i', 'url(\1'. $directory, $file);
 }
+
+/**
+ * Perform an HTTP request; does not wait for reply & you will never get it
+ * back.
+ *
+ * @see drupal_http_request
+ *
+ * This is a flexible and powerful HTTP client implementation. Correctly
+ * handles GET, POST, PUT or any other HTTP requests.
+ *
+ * @param $url
+ *   A string containing a fully qualified URI.
+ * @param array $options
+ *   (optional) An array that can have one or more of the following elements:
+ *   - headers: An array containing request headers to send as name/value pairs.
+ *   - method: A string containing the request method. Defaults to 'GET'.
+ *   - data: A string containing the request body, formatted as
+ *     'param=value&param=value&...'. Defaults to NULL.
+ *   - max_redirects: An integer representing how many times a redirect
+ *     may be followed. Defaults to 3.
+ *   - timeout: A float representing the maximum number of seconds the function
+ *     call may take. The default is 30 seconds. If a timeout occurs, the error
+ *     code is set to the HTTP_REQUEST_TIMEOUT constant.
+ *   - context: A context resource created with stream_context_create().
+ * @return bool
+ *   return value from advagg_async_send_http_request().
+ */
+function advagg_async_connect_http_request($url, array $options = array()) {
+  $result = new stdClass();
+
+  // Parse the URL and make sure we can handle the schema.
+  $uri = @parse_url($url);
+
+  if ($uri == FALSE) {
+    $result->error = 'unable to parse URL';
+    $result->code = -1001;
+    return $result;
+  }
+
+  if (!isset($uri['scheme'])) {
+    $result->error = 'missing schema';
+    $result->code = -1002;
+    return $result;
+  }
+
+  // Merge the default options.
+  $options += array(
+    'headers' => array(),
+    'method' => 'GET',
+    'data' => NULL,
+    'max_redirects' => 3,
+    'timeout' => 30.0,
+    'context' => NULL,
+  );
+  // stream_socket_client() requires timeout to be a float.
+  $options['timeout'] = (float) $options['timeout'];
+
+  switch ($uri['scheme']) {
+    case 'http':
+    case 'feed':
+      $port = isset($uri['port']) ? $uri['port'] : 80;
+      $socket = 'tcp://' . $uri['host'] . ':' . $port;
+      // RFC 2616: "non-standard ports MUST, default ports MAY be included".
+      // We don't add the standard port to prevent from breaking rewrite rules
+      // checking the host that do not take into account the port number.
+      if (empty($options['headers']['Host'])) {
+        $options['headers']['Host'] = $uri['host'];
+      }
+      if ($port != 80) {
+        $options['headers']['Host'] .= ':' . $port;
+      }
+      break;
+    case 'https':
+      // Note: Only works when PHP is compiled with OpenSSL support.
+      $port = isset($uri['port']) ? $uri['port'] : 443;
+      $socket = 'ssl://' . $uri['host'] . ':' . $port;
+      if (empty($options['headers']['Host'])) {
+        $options['headers']['Host'] = $uri['host'];
+      }
+      if ($port != 443) {
+        $options['headers']['Host'] .= ':' . $port;
+      }
+      break;
+    default:
+      $result->error = 'invalid schema ' . $uri['scheme'];
+      $result->code = -1003;
+      return $result;
+  }
+
+  if (empty($options['context'])) {
+    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout'], STREAM_CLIENT_ASYNC_CONNECT|STREAM_CLIENT_CONNECT);
+  }
+  else {
+    // Create a stream with context. Allows verification of a SSL certificate.
+    $fp = @stream_socket_client($socket, $errno, $errstr, $options['timeout'], STREAM_CLIENT_ASYNC_CONNECT|STREAM_CLIENT_CONNECT, $options['context']);
+  }
+
+  // Make sure the socket opened properly.
+  if (!$fp) {
+    // When a network error occurs, we use a negative number so it does not
+    // clash with the HTTP status codes.
+    $result->code = -$errno;
+    $result->error = trim($errstr) ? trim($errstr) : t('Error opening socket @socket', array('@socket' => $socket));
+
+    return $result;
+  }
+
+  // Non blocking stream.
+  stream_set_blocking($fp, 0);
+
+  // Construct the path to act on.
+  $path = isset($uri['path']) ? $uri['path'] : '/';
+  if (isset($uri['query'])) {
+    $path .= '?' . $uri['query'];
+  }
+
+  // Merge the default headers.
+  $options['headers'] += array(
+    'User-Agent' => 'Drupal (+http://drupal.org/)',
+  );
+
+  // Only add Content-Length if we actually have any content or if it is a POST
+  // or PUT request. Some non-standard servers get confused by Content-Length in
+  // at least HEAD/GET requests, and Squid always requires Content-Length in
+  // POST/PUT requests.
+  $content_length = strlen($options['data']);
+  if ($content_length > 0 || $options['method'] == 'POST' || $options['method'] == 'PUT') {
+    $options['headers']['Content-Length'] = $content_length;
+  }
+
+  // If the server URL has a user then attempt to use basic authentication.
+  if (isset($uri['user'])) {
+    $options['headers']['Authorization'] = 'Basic ' . base64_encode($uri['user'] . (!empty($uri['pass']) ? ":" . $uri['pass'] : ''));
+  }
+
+  // If the database prefix is being used by SimpleTest to run the tests in a copied
+  // database then set the user-agent header to the database prefix so that any
+  // calls to other Drupal pages will run the SimpleTest prefixed database. The
+  // user-agent is used to ensure that multiple testing sessions running at the
+  // same time won't interfere with each other as they would if the database
+  // prefix were stored statically in a file or database variable.
+  $test_info = &$GLOBALS['drupal_test_info'];
+  if (!empty($test_info['test_run_id'])) {
+    $options['headers']['User-Agent'] = drupal_generate_test_ua($test_info['test_run_id']);
+  }
+
+  $request = $options['method'] . ' ' . $path . " HTTP/1.0\r\n";
+  foreach ($options['headers'] as $name => $value) {
+    $request .= $name . ': ' . trim($value) . "\r\n";
+  }
+  $request .= "\r\n" . $options['data'];
+  $result->request = $request;
+
+  return advagg_async_send_http_request($fp, $request, $options['timeout']);
+}
+
+/**
+ * Perform an HTTP request; does not wait for reply & you never will get it
+ * back.
+ *
+ * @see drupal_http_request
+ *
+ * This is a flexible and powerful HTTP client implementation. Correctly
+ * handles GET, POST, PUT or any other HTTP requests.
+ *
+ * @param $fp
+ *   (optional) A file pointer.
+ * @param $request
+ *   (optional) A string containing the request headers to send to the server.
+  * @param $timeout
+ *   (optional) An interger holding the stream timeout value.
+ * @return bool
+ *   TRUE if function worked as planed.
+ */
+function advagg_async_send_http_request($fp = NULL, $request = '', $timeout = 1) {
+  static $requests = array();
+  static $registered = FALSE;
+
+  // Store data in a static, and register a shutdown function.
+  $args = array($fp, $request, $timeout);
+  if (!empty($fp)) {
+    $requests[] = $args;
+    if (!$registered) {
+      register_shutdown_function(__FUNCTION__);
+      $registered = TRUE;
+    }
+    return TRUE;
+  }
+
+  // Shutdown function run.
+  if (empty($requests)) {
+    return FALSE;
+  }
+
+  $streams = array();
+  foreach ($requests as $id => $values) {
+    list($fp, $request, $timeout) = $values;
+    $streams[$id] = $fp;
+  }
+
+  $retry_count = 2;
+  // Run the loop as long as we have a stream to write to.
+  while (!empty($streams)) {
+    // Set the read and write vars to the streams var.
+    $read = $write = $streams;
+    $except = array();
+
+    // Do some voodoo and open all streams at once.
+    $n = stream_select($read, $write, $except, $timeout);
+
+    // We have some streams to write to.
+    if (!empty($n)) {
+      // Write to each stream if it is available.
+      foreach ($write as $id => $w) {
+        fwrite($w, $requests[$id][1]);
+        fclose($w);
+        unset($streams[$id]);
+      }
+    }
+    // Timed out waiting or all $streams are closed at this point.
+    elseif (!empty($retry_count)) {
+      $retry_count--;
+    }
+    else {
+      break;
+    }
+  }
+  // Free memory.
+  $requests = array();
+  return TRUE;
+}