diff --git a/Models/Risk.php b/Models/Risk.php
index 0a0c5f7..95708e2 100755
--- a/Models/Risk.php
+++ b/Models/Risk.php
@@ -89,7 +89,7 @@ class Risk
      */
     public function __construct()
     {
-        $this->createdAt = new \DateTime('now');
+        $this->createdAt = new \DateTimeImmutable('now');
     }
 
     /**
diff --git a/Models/RiskMapper.php b/Models/RiskMapper.php
index 4806a8d..bf3ebcc 100755
--- a/Models/RiskMapper.php
+++ b/Models/RiskMapper.php
@@ -46,7 +46,7 @@ final class RiskMapper extends DataMapperAbstract
         'riskmngmt_risk_process'        => ['name' => 'riskmngmt_risk_process',        'type' => 'int',      'internal' => 'process'],
         'riskmngmt_risk_responsible'    => ['name' => 'riskmngmt_risk_responsible',    'type' => 'int',      'internal' => 'responsible'],
         'riskmngmt_risk_deputy'         => ['name' => 'riskmngmt_risk_deputy',         'type' => 'int',      'internal' => 'deputy'],
-        'riskmngmt_risk_created_at'     => ['name' => 'riskmngmt_risk_created_at',     'type' => 'DateTime', 'internal' => 'createdAt', 'readonly' => true],
+        'riskmngmt_risk_created_at'     => ['name' => 'riskmngmt_risk_created_at',     'type' => 'DateTimeImmutable', 'internal' => 'createdAt', 'readonly' => true],
     ];
 
     /**