diff --git a/modules/openid/openid.module b/modules/openid/openid.module
index e70f158ad2a..48bf7e33cf0 100644
--- a/modules/openid/openid.module
+++ b/modules/openid/openid.module
@@ -477,17 +477,16 @@ function openid_association_request($public) {
 function openid_authentication_request($claimed_id, $identity, $return_to = '', $assoc_handle = '', $version = 2) {
   module_load_include('inc', 'openid');
 
-  $ns = ($version == 2) ? OPENID_NS_2_0 : OPENID_NS_1_0;
   $request =  array(
-    'openid.ns' => $ns,
     'openid.mode' => 'checkid_setup',
     'openid.identity' => $identity,
-    'openid.claimed_id' => $claimed_id,
     'openid.assoc_handle' => $assoc_handle,
     'openid.return_to' => $return_to,
   );
 
   if ($version == 2) {
+    $request['openid.ns'] = OPENID_NS_2_0;
+    $request['openid.claimed_id'] = $claimed_id;
     $request['openid.realm'] = url('', array('absolute' => TRUE));
   }
   else {
diff --git a/modules/openid/tests/openid_test.module b/modules/openid/tests/openid_test.module
index c84b1028475..7312330098e 100644
--- a/modules/openid/tests/openid_test.module
+++ b/modules/openid/tests/openid_test.module
@@ -206,10 +206,11 @@ function _openid_test_endpoint_authenticate() {
   // entries contain profile data stored by the OpenID Provider (see OpenID
   // Simple Registration Extension 1.0).
   $response = array(
-    'openid.ns' => 'http://specs.openid.net/auth/2.0',
+    'openid.ns' => OPENID_NS_2_0,
     'openid.mode' => 'id_res',
     'openid.op_endpoint' => $base_url . url('openid/provider'),
-    'openid.claimed_id' => $_REQUEST['openid_claimed_id'],
+    // openid.claimed_id is not sent by OpenID 1 clients.
+    'openid.claimed_id' => isset($_REQUEST['openid_claimed_id']) ? $_REQUEST['openid_claimed_id'] : '',
     'openid.identity' => $_REQUEST['openid_identity'],
     'openid.return_to' => $_REQUEST['openid_return_to'],
     'openid.response_nonce' => $nonce,