diff --git a/src/Parse/ParseUser.php b/src/Parse/ParseUser.php
index e559b176..e6410f31 100644
--- a/src/Parse/ParseUser.php
+++ b/src/Parse/ParseUser.php
@@ -51,6 +51,7 @@ public function getUsername()
      */
     public function setUsername($username)
     {
+        $this->set('authData.anonymous', null);
         return $this->set('username', $username);
     }
 
diff --git a/tests/Parse/ParseUserTest.php b/tests/Parse/ParseUserTest.php
index 1f101d24..6be0a1c3 100644
--- a/tests/Parse/ParseUserTest.php
+++ b/tests/Parse/ParseUserTest.php
@@ -759,4 +759,15 @@ public function testRequestVerificationEmailBad()
         $this->setExpectedException('Parse\ParseException', 'No user found with email not_a_known_email');
         ParseUser::requestVerificationEmail('not_a_known_email');
     }
+
+    public function testRegisteringAnonymousClearsAuthData()
+    {
+        $user = ParseUser::loginWithAnonymous();
+        $response = ParseClient::_request('GET', 'users', null, null, true);
+        $this->assertNotNull($response['results'][0]['authData']['anonymous']);
+        $user->setUsername('Mary');
+        $user->save();
+        $response = ParseClient::_request('GET', 'users', null, null, true);
+        $this->assertArrayNotHasKey('authData', $response['results'][0])    ;
+    }
 }