diff --git a/tests/PHPUnit/Integration/TrackingAPI_SetVisitorIdTest.php b/tests/PHPUnit/Integration/TrackingAPI_SetVisitorIdTest.php
index 611d612c17f6110b842497fd3569021ab09cf046..e43c9aabe21dcc12d8292fd4539b713281df0703 100644
--- a/tests/PHPUnit/Integration/TrackingAPI_SetVisitorIdTest.php
+++ b/tests/PHPUnit/Integration/TrackingAPI_SetVisitorIdTest.php
@@ -98,16 +98,19 @@ class Test_Piwik_Integration_TrackingAPI_SetVisitorId extends IntegrationTestCas
     {
         try {
             $t->setVisitorId('test');
+            $this->fail('should throw');
         } catch(Exception $e) {
             //OK
         }
         try {
             $t->setVisitorId('61e8');
+            $this->fail('should throw');
         } catch(Exception $e) {
             //OK
         }
         try {
             $t->setVisitorId('61e8cc2d51fea26dabcabcabc');
+            $this->fail('should throw');
         } catch(Exception $e) {
             //OK
         }