diff --git a/src/League/OAuth2/Server/Grant/AuthCode.php b/src/League/OAuth2/Server/Grant/AuthCode.php
index 70447a41..08f1a7c2 100644
--- a/src/League/OAuth2/Server/Grant/AuthCode.php
+++ b/src/League/OAuth2/Server/Grant/AuthCode.php
@@ -276,7 +276,7 @@ class AuthCode implements GrantTypeInterface {
 
         $response = array(
             'access_token'  =>  $accessToken,
-            'token_type'    =>  'bearer',
+            'token_type'    =>  'Bearer',
             'expires'       =>  $accessTokenExpires,
             'expires_in'    =>  $accessTokenExpiresIn
         );
@@ -292,4 +292,4 @@ class AuthCode implements GrantTypeInterface {
         return $response;
     }
 
-}
\ No newline at end of file
+}