diff --git a/core/Tracker/Request.php b/core/Tracker/Request.php
index b733ae30eae1c6d28b3d17f6dae53d83a367c024..110d0eb65d4af87bdd85868eb0c45f68805e1632 100644
--- a/core/Tracker/Request.php
+++ b/core/Tracker/Request.php
@@ -12,6 +12,7 @@ use Exception;
 use Piwik\Common;
 use Piwik\Config;
 use Piwik\Cookie;
+use Piwik\Exception\UnexpectedWebsiteFoundException;
 use Piwik\IP;
 use Piwik\Network\IPUtils;
 use Piwik\Piwik;
@@ -390,7 +391,7 @@ class Request
         Piwik::postEvent('Tracker.Request.getIdSite', array(&$idSite, $this->params));
 
         if ($idSite <= 0) {
-            throw new Exception('Invalid idSite: \'' . $idSite . '\'');
+            throw new UnexpectedWebsiteFoundException('Invalid idSite: \'' . $idSite . '\'');
         }
 
         return $idSite;
diff --git a/tests/PHPUnit/System/TrackerTest.php b/tests/PHPUnit/System/TrackerTest.php
index 29ba0c95e5cb64773e264e1eac23bd2cac978bb7..baba28e7631c2443da61f08e94884ecd3aff6968 100755
--- a/tests/PHPUnit/System/TrackerTest.php
+++ b/tests/PHPUnit/System/TrackerTest.php
@@ -77,4 +77,12 @@ class TrackerTest extends SystemTestCase
         $this->assertResponseCode(400, $url);
     }
 
+    public function test_response_ShouldSend400ResponseCode_IfSiteIdIsZero()
+    {
+        $url = $this->tracker->getUrlTrackPageView('Test');
+        $url .= '&idsite=0';
+
+        $this->assertResponseCode(400, $url);
+    }
+
 }