diff --git a/phpunit.xml b/phpunit.xml
index d31e033..cbf6c18 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -11,4 +11,11 @@
             <directory>tests/*</directory>
         </testsuite>
     </testsuites>​
+
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">src</directory>
+        </whitelist>
+    </filter>
+
 </phpunit>