diff --git a/phpunit.xml b/phpunit.xml
index d752125..230a781 100644
--- a/phpunit.xml
+++ b/phpunit.xml
@@ -1,4 +1,9 @@
 <phpunit bootstrap="./vendor/autoload.php">
+    <testsuites>
+        <testsuite name="units">
+            <directory>tests</directory>
+        </testsuite>
+    </testsuites>
     <logging>
         <log type="coverage-html" target="build/coverage" lowUpperBound="35" highLowerBound="70"/>
         <log type="coverage-clover" target="build/logs/clover.xml"/>