diff --git a/src/Bundle/ChillMainBundle/Entity/User.php b/src/Bundle/ChillMainBundle/Entity/User.php
index 140e0889c..41d6db40c 100644
--- a/src/Bundle/ChillMainBundle/Entity/User.php
+++ b/src/Bundle/ChillMainBundle/Entity/User.php
@@ -44,7 +44,8 @@ class User implements AdvancedUserInterface {
      * @ORM\Column(
      *     type="string",
      *     length=80,
-     *     unique=true)
+     *     unique=true,
+     *     nullable=true)
      */
     private $usernameCanonical;
 
diff --git a/src/Bundle/ChillMainBundle/migrations/Version20210903144853.php b/src/Bundle/ChillMainBundle/migrations/Version20210903144853.php
index 4e252c3a3..7fe6b8e72 100644
--- a/src/Bundle/ChillMainBundle/migrations/Version20210903144853.php
+++ b/src/Bundle/ChillMainBundle/migrations/Version20210903144853.php
@@ -28,7 +28,6 @@ final class Version20210903144853 extends AbstractMigration
         $this->addSql('ALTER TABLE users ADD mainCenter_id INT DEFAULT NULL');
         $this->addSql('ALTER TABLE users ADD mainScope_id INT DEFAULT NULL');
         $this->addSql('ALTER TABLE users ADD userJob_id INT DEFAULT NULL');
-        $this->addSql('ALTER TABLE users ALTER usernamecanonical SET NOT NULL');
         $this->addSql('ALTER TABLE users ADD CONSTRAINT FK_1483A5E92C2125C1 FOREIGN KEY (mainCenter_id) REFERENCES centers (id) NOT DEFERRABLE INITIALLY IMMEDIATE');
         $this->addSql('ALTER TABLE users ADD CONSTRAINT FK_1483A5E9115E73F3 FOREIGN KEY (mainScope_id) REFERENCES scopes (id) NOT DEFERRABLE INITIALLY IMMEDIATE');
         $this->addSql('ALTER TABLE users ADD CONSTRAINT FK_1483A5E964B65C5B FOREIGN KEY (userJob_id) REFERENCES chill_main_user_job (id) NOT DEFERRABLE INITIALLY IMMEDIATE');