diff --git a/main/mashape/http/AuthUtil.php b/main/mashape/http/AuthUtil.php
index 3b6a928..a18358b 100755
--- a/main/mashape/http/AuthUtil.php
+++ b/main/mashape/http/AuthUtil.php
@@ -29,9 +29,8 @@ class AuthUtil {
 	public static function generateAuthenticationHeader($publicKey, $privateKey) {
 		$header = "";
 		if (!($publicKey == null || $privateKey == null)) {
-			$uuid = uniqid();
-			$hash = hash_hmac("sha1", $uuid, $privateKey);
-			$header = "X-Mashape-Authorization: " . base64_encode($publicKey . ":" . $hash . $uuid) . "\r\n";
+			$hash = hash_hmac("sha1", $publicKey, $privateKey);
+			$header = "Proxy-Authorization: " . base64_encode($publicKey . ":" . $hash) . "\r\n";
 		}
 		return $header;
 	}