diff --git a/Models/Account.php b/Models/Account.php
index 00b5f24..37d57e5 100644
--- a/Models/Account.php
+++ b/Models/Account.php
@@ -30,7 +30,7 @@ class Account extends \phpOMS\Account\Account
      * @var int
      * @since 1.0.0
      */
-    protected $tries = 0;
+    protected int $tries = 0;
 
     /**
      * Get remaining login tries
diff --git a/Models/AccountPermission.php b/Models/AccountPermission.php
index 176121b..2baa541 100644
--- a/Models/AccountPermission.php
+++ b/Models/AccountPermission.php
@@ -35,7 +35,7 @@ class AccountPermission extends PermissionAbstract
      * @var int
      * @since 1.0.0
      */
-    private $account = 0;
+    private int $account = 0;
 
     /**
      * Constructor.
diff --git a/Models/Group.php b/Models/Group.php
index b760a4d..0eb7c20 100644
--- a/Models/Group.php
+++ b/Models/Group.php
@@ -30,7 +30,7 @@ class Group extends \phpOMS\Account\Group
      * @var null|\DateTime
      * @since 1.0.0
      */
-    protected $createdAt = null;
+    protected ?\DateTime $createdAt = null;
 
     /**
      * Created by.
@@ -46,7 +46,7 @@ class Group extends \phpOMS\Account\Group
      * @var string
      * @since 1.0.0
      */
-    protected $descriptionRaw = '';
+    protected string $descriptionRaw = '';
 
     /**
      * Accounts
@@ -54,7 +54,7 @@ class Group extends \phpOMS\Account\Group
      * @var array
      * @since 1.0.0
      */
-    protected $accounts = [];
+    protected array $accounts = [];
 
     /**
      * Constructor
diff --git a/Models/GroupPermission.php b/Models/GroupPermission.php
index 65a2c01..fb08326 100644
--- a/Models/GroupPermission.php
+++ b/Models/GroupPermission.php
@@ -35,7 +35,7 @@ class GroupPermission extends PermissionAbstract
      * @var int
      * @since 1.0.0
      */
-    private $group = 0;
+    private int $group = 0;
 
     /**
      * Constructor.
diff --git a/Models/Module.php b/Models/Module.php
index c985c75..68a1ba8 100644
--- a/Models/Module.php
+++ b/Models/Module.php
@@ -33,7 +33,7 @@ class Module
      * @var int
      * @since 1.0.0
      */
-    protected $id = 0;
+    protected int $id = 0;
 
     /**
      * Account name.
@@ -41,7 +41,7 @@ class Module
      * @var string
      * @since 1.0.0
      */
-    protected $name = '';
+    protected string $name = '';
 
     /**
      * Account name.
@@ -49,7 +49,7 @@ class Module
      * @var string
      * @since 1.0.0
      */
-    protected $description = '';
+    protected string $description = '';
 
     /**
      * Group status.
@@ -57,7 +57,7 @@ class Module
      * @var int
      * @since 1.0.0
      */
-    protected $status = ModuleStatus::INACTIVE;
+    protected int $status = ModuleStatus::INACTIVE;
 
     /**
      * Created at.
@@ -65,7 +65,7 @@ class Module
      * @var null|\DateTime
      * @since 1.0.0
      */
-    protected $createdAt = null;
+    protected ?\DateTime $createdAt = null;
 
     /**
      * Constructor.