diff --git a/lib/Cake/TestSuite/Reporter/CakeHtmlReporter.php b/lib/Cake/TestSuite/Reporter/CakeHtmlReporter.php
index 73da81ca4..407045739 100644
--- a/lib/Cake/TestSuite/Reporter/CakeHtmlReporter.php
+++ b/lib/Cake/TestSuite/Reporter/CakeHtmlReporter.php
@@ -264,7 +264,7 @@ class CakeHtmlReporter extends CakeBaseReporter {
 		echo "<div class='msg'><pre>" . $this->_htmlEntities($message->toString());
 
 		if ((is_string($actualMsg) && is_string($expectedMsg)) || (is_array($actualMsg) && is_array($expectedMsg))) {
-			echo "<br />" . PHPUnit_Util_Diff::diff($expectedMsg, $actualMsg);
+			echo "<br />" . $this->_htmlEntities(PHPUnit_Util_Diff::diff($expectedMsg, $actualMsg));
 		}
 
 		echo "</pre></div>\n";