diff --git a/src/Customer/Infrastructure/Repository.php b/src/Customer/Infrastructure/Repository.php
index ed162161..b902935e 100644
--- a/src/Customer/Infrastructure/Repository.php
+++ b/src/Customer/Infrastructure/Repository.php
@@ -91,7 +91,7 @@ public function getCustomerByPasswordUpdateId(string $passwordUpdateId): EshopUs
     {
         $user = $this->oxNewFactory->getModel(EshopUserModel::class);
         $user = $user->loadUserByUpdateId($passwordUpdateId);
-        if (!$user->isLoaded()) {
+        if (!$user instanceof EshopUserModel || !$user->isLoaded()) {
             throw new CustomerNotFoundByUpdateId($passwordUpdateId);
         }
 
diff --git a/tests/Unit/Customer/Infrastructure/RepositoryTest.php b/tests/Unit/Customer/Infrastructure/RepositoryTest.php
index 45917c2b..9489e377 100644
--- a/tests/Unit/Customer/Infrastructure/RepositoryTest.php
+++ b/tests/Unit/Customer/Infrastructure/RepositoryTest.php
@@ -58,7 +58,7 @@ public function testGetCustomerByPasswordUpdateId(): void
         $repository->getCustomerByPasswordUpdateId($passwordUpdateId);
     }
 
-    public function testCustomerByPasswordUpdateIdNotFound(): void
+    public function testCustomerByPasswordUpdateIdNotLoaded(): void
     {
         $passwordUpdateId = 'wrongId';
 
@@ -76,4 +76,22 @@ public function testCustomerByPasswordUpdateIdNotFound(): void
         $repository = new Repository($sharedRepository, $oxNewFactory);
         $repository->getCustomerByPasswordUpdateId($passwordUpdateId);
     }
+
+    public function testCustomerByPasswordUpdateIdNotFound(): void
+    {
+        $passwordUpdateId = 'wrongId';
+
+        $userMock = $this->createMock(User::class);
+        $userMock->expects($this->once())->method('loadUserByUpdateId')->with($passwordUpdateId)->willReturn(null);
+
+        $sharedRepository = $this->createMock(RepositoryInterface::class);
+        $oxNewFactory = $this->createMock(OxNewFactoryInterface::class);
+        $oxNewFactory->expects($this->once())->method('getModel')->with(User::class)->willReturn($userMock);
+
+        $this->expectException(CustomerNotFoundByUpdateId::class);
+        $this->expectExceptionMessage('No customer was found by update id: "wrongId".');
+
+        $repository = new Repository($sharedRepository, $oxNewFactory);
+        $repository->getCustomerByPasswordUpdateId($passwordUpdateId);
+    }
 }