diff --git a/src/Symfony/Component/Templating/PhpEngine.php b/src/Symfony/Component/Templating/PhpEngine.php
index de41affd2a..521ae61085 100644
--- a/src/Symfony/Component/Templating/PhpEngine.php
+++ b/src/Symfony/Component/Templating/PhpEngine.php
@@ -17,6 +17,10 @@ use Symfony\Component\Templating\Storage\StringStorage;
 use Symfony\Component\Templating\Helper\HelperInterface;
 use Symfony\Component\Templating\Loader\LoaderInterface;
 
+if (!defined('ENT_SUBSTITUTE')) {
+    define('ENT_SUBSTITUTE', 8);
+}
+
 /**
  * PhpEngine is an engine able to render PHP templates.
  *
@@ -440,7 +444,7 @@ class PhpEngine implements EngineInterface, \ArrayAccess
                 {
                     // Numbers and Boolean values get turned into strings which can cause problems
                     // with type comparisons (e.g. === or is_int() etc).
-                    return is_string($value) ? htmlspecialchars($value, ENT_QUOTES, $that->getCharset(), false) : $value;
+                    return is_string($value) ? htmlspecialchars($value, ENT_QUOTES | ENT_SUBSTITUTE, $that->getCharset(), false) : $value;
                 },
 
             'js' =>