diff --git a/app/Mail/PasswordChanged.php b/app/Mail/PasswordChanged.php
index 6b9d7f18..a0202ade 100644
--- a/app/Mail/PasswordChanged.php
+++ b/app/Mail/PasswordChanged.php
@@ -11,11 +11,10 @@ class PasswordChanged extends Mailable
     use Queueable;
     use SerializesModels;
 
-    protected $updated_at;
-
-    public function __construct($updated_at)
-    {
-        $this->updated_at = $updated_at;
+    public function __construct(
+        protected $updated_at,
+    ) {
+        //
     }
 
     public function build()
diff --git a/tests/Unit/Mail/PasswordChangedTest.php b/tests/Unit/Mail/PasswordChangedTest.php
new file mode 100644
index 00000000..c557f9b1
--- /dev/null
+++ b/tests/Unit/Mail/PasswordChangedTest.php
@@ -0,0 +1,16 @@
+<?php
+
+namespace Tests\Unit\Mail;
+
+use App\Mail\PasswordChanged;
+use Tests\TestCase;
+
+class PasswordChangedTest extends TestCase
+{
+    public function testMailable(): void
+    {
+        $mailable = new PasswordChanged('2023-12-05 18:00:00');
+
+        $mailable->assertSeeInText('Heads up! Your password has been changed (2023-12-05 18:00:00 CEST).');
+    }
+}