diff --git a/Auth/OpenID/Server.php b/Auth/OpenID/Server.php
index <HASH>..<HASH> 100644
--- a/Auth/OpenID/Server.php
+++ b/Auth/OpenID/Server.php
@@ -182,8 +182,8 @@ class Auth_OpenID_ServerError {
         }
 
         return Auth_OpenID::appendArgs($return_to,
-                                       array('openid.mode' => 'error',
-                                             'error' => $this->toString()));
+                            array('openid.mode' => 'error',
+                                  'openid.error' => $this->toString()));
     }
 
     /**
diff --git a/Tests/Auth/OpenID/Server.php b/Tests/Auth/OpenID/Server.php
index <HASH>..<HASH> 100644
--- a/Tests/Auth/OpenID/Server.php
+++ b/Tests/Auth/OpenID/Server.php
@@ -46,7 +46,7 @@ class Tests_Auth_OpenID_Test_ServerError extends PHPUnit_TestCase {
         $this->assertTrue($e->hasReturnTo());
         $expected_args = array(
             'openid.mode' => 'error',
-            'error' => 'plucky');
+            'openid.error' => 'plucky');
 
         $encoded = $e->encodeToURL();
         if (_isError($encoded)) {
[project @ BUGFIX: Fixed error reporting in server request encoding]