diff --git a/README.md b/README.md
index edbd0ac..7621df5 100644
--- a/README.md
+++ b/README.md
@@ -24,14 +24,18 @@ PHP client library is located in `lib/php/premium-api.php`. An usage example is
 Requirements:
 * [PHP 5.5 or newer](http://www.php.net/)
 * One of these:
-    * [pecl_http](http://pecl.php.net/package/pecl_http) extension is recommended but not mandatory.
-    * enabled [cURL library](http://www.php.net/manual/en/book.curl.php).
+    * [cURL extension](http://www.php.net/manual/en/book.curl.php).
+    * [pecl_http](http://pecl.php.net/package/pecl_http) extension.
     * [allow_url_fopen](http://php.net/manual/en/filesystem.configuration.php) set to true (attachment file upload is not currently supported for this method.)
 
 Library usage is [described in the wiki](https://github.com/Sales-LV/premium-api/wiki/PHP-API-library).
 
 Changelog
 ------------
+1.3.0:
+- Changed to prefer cURL for making HTTP requests.
+- PHP version number passed to Premium in user agent.
+
 1.2.1:
 - Minor fixes for PHP 8.1 compatibility.
 
diff --git a/lib/php/premium-api.php b/lib/php/premium-api.php
index 8fa1f13..72c8c7e 100644
--- a/lib/php/premium-api.php
+++ b/lib/php/premium-api.php
@@ -6,7 +6,7 @@
  */
 class PremiumAPI
 {
-	private static $Version = '1.2.1';
+	private static $Version = '1.3.0';
 	private static $UserAgent = 'SalesLV/Premium-API';
 	private static $UAString = '';
 
@@ -133,6 +133,7 @@ public function __construct($Key, $CampaignCode)
 		{
 			self::$UAString .= '-stream';
 		}
+		self::$UAString .= '/php'.PHP_VERSION;
 
 		$this -> APIKey = $Key;
 		$this -> CampaignCode = $CampaignCode;
@@ -188,7 +189,6 @@ public function Messages_Get($ID)
 		return $this -> ParseResponse($Data);
 	}
 
-
 	/**
 	 * Method for retrieving a message list from a campaign by the given parameters
 	 *
@@ -325,7 +325,8 @@ private function SetError($ErrorCode, $ErrorMessage)
 	 *
 	 * @param string URL to make the request to
 	 * @param array POST data if it is a POST request. If this is empty, a GET request will be made, if populated - POST. Optional.
-	 * @param array Additional headers to pass to the service, optional.
+	 * @param array Additional headers to pass to the service, optional. Each item in the array is a string with a complete header including name
+	 *  and value, e.g. "Content-Type: application/x-www-form-urlencoded".
 	 *
 	 * @return array Array containing response data: array(
 	 *	'Code' => int HTTP status code (200, 403, etc.),
@@ -342,15 +343,21 @@ private function HTTPRequest($URL, array $POSTData = null, array $Headers = null
 
 		$Result = [];
 
+		if (!$Headers)
+		{
+			$Headers = [];
+		}
+		$Headers[] = 'Content-Type: application/x-www-form-urlencoded';
+
 		try
 		{
-			if (extension_loaded('http'))
+			if (extension_loaded('curl'))
 			{
-				$Result = self::HTTPRequest_http($URL, $POSTData, $Headers, $Files);
+				$Result = self::HTTPRequest_curl($URL, $POSTData, $Headers, $Files);
 			}
-			elseif (extension_loaded('curl'))
+			elseif (extension_loaded('http'))
 			{
-				$Result = self::HTTPRequest_curl($URL, $POSTData, $Headers, $Files);
+				$Result = self::HTTPRequest_http($URL, $POSTData, $Headers, $Files);
 			}
 			elseif (ini_get('allow_url_fopen'))
 			{