diff --git a/Models/Audit.php b/Models/Audit.php
index 04df210..f442e22 100755
--- a/Models/Audit.php
+++ b/Models/Audit.php
@@ -109,7 +109,7 @@ class Audit
      * @var \DateTime
      * @since 1.0.0
      */
-    private \DateTime $createdAt;
+    private \DateTimeImmutable $createdAt;
 
     /**
      * Ip of creator.
@@ -145,7 +145,7 @@ class Audit
         string $content = null,
         int $ip = 0
     ) {
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
         $this->createdBy = $account ?? new NullAccount();
         $this->old       = $old;
         $this->new       = $new;
@@ -274,7 +274,7 @@ class Audit
      *
      * @since 1.0.0
      */
-    public function getCreatedAt() : \DateTime
+    public function getCreatedAt() : \DateTimeInterface
     {
         return $this->createdAt;
     }
diff --git a/Models/AuditMapper.php b/Models/AuditMapper.php
index 7439999..452154e 100755
--- a/Models/AuditMapper.php
+++ b/Models/AuditMapper.php
@@ -36,7 +36,7 @@ final class AuditMapper extends DataMapperAbstract
     protected static array $columns = [
         'auditor_audit_id'         => ['name' => 'auditor_audit_id',         'type' => 'int',      'internal' => 'id'],
         'auditor_audit_created_by' => ['name' => 'auditor_audit_created_by', 'type' => 'int',      'internal' => 'createdBy', 'readonly' => true],
-        'auditor_audit_created_at' => ['name' => 'auditor_audit_created_at', 'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'auditor_audit_created_at' => ['name' => 'auditor_audit_created_at', 'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
         'auditor_audit_ip'         => ['name' => 'auditor_audit_ip',         'type' => 'int',      'internal' => 'ip', 'annotations' => ['gdpr' => true]],
         'auditor_audit_module'     => ['name' => 'auditor_audit_module',     'type' => 'string',   'internal' => 'module'],
         'auditor_audit_ref'        => ['name' => 'auditor_audit_ref',        'type' => 'string',   'internal' => 'ref'],
diff --git a/tests/Models/AuditTest.php b/tests/Models/AuditTest.php
index e641847..d9d7a5f 100755
--- a/tests/Models/AuditTest.php
+++ b/tests/Models/AuditTest.php
@@ -41,7 +41,7 @@ class AuditTest extends \PHPUnit\Framework\TestCase
         self::assertNull($audit->getOld());
         self::assertNull($audit->getNew());
         self::assertEquals(0, $audit->getCreatedBy()->getId());
-        self::assertInstanceOf('\DateTime', $audit->getCreatedAt());
+        self::assertInstanceOf('\DateTimeImmutable', $audit->getCreatedAt());
     }
 
     /**