diff --git a/test/integration/CustomerTest.php b/test/integration/CustomerTest.php
index c8a1b5be..e31ecdb9 100755
--- a/test/integration/CustomerTest.php
+++ b/test/integration/CustomerTest.php
@@ -335,6 +335,7 @@ public function customerShouldBeFetchedByCustomerIdAndUpdatedIfItAlreadyExists()
         try {
             // fetch non-existing customer by customerId
             $this->heidelpay->fetchCustomerByExtCustomerId($customerId);
+            $this->assertTrue(false, 'Exception should be thrown here.');
         } catch (HeidelpayApiException $e) {
             $this->assertEquals($e->getCode(), ApiResponseCodes::API_ERROR_CUSTOMER_CAN_NOT_BE_FOUND);
         }