diff --git a/tests/HTMLPurifier/AttrDef/CSS/CompositeTest.php b/tests/HTMLPurifier/AttrDef/CSS/CompositeTest.php
index 3ec60e7d..0a4e496f 100644
--- a/tests/HTMLPurifier/AttrDef/CSS/CompositeTest.php
+++ b/tests/HTMLPurifier/AttrDef/CSS/CompositeTest.php
@@ -40,8 +40,8 @@ class HTMLPurifier_AttrDef_CSS_CompositeTest extends HTMLPurifier_AttrDefHarness
         $def1->setReturnValue('validate', $output, $def1_params);
         $def2->expectNever('validate');
         
-        $this->assertIdentical($output,
-            $def->validate($input, $config, $context));
+        $result = $def->validate($input, $config, $context);
+        $this->assertIdentical($output, $result);
         
         $def1->tally();
         $def2->tally();