diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index 021d3de1ee..278ffc0743 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -553,7 +553,7 @@ class Request
     public static function setTrustedHosts(array $hostPatterns)
     {
         self::$trustedHostPatterns = array_map(function ($hostPattern) {
-            return sprintf('{%s}i', str_replace('}', '\\}', $hostPattern));
+            return sprintf('#%s#i', $hostPattern);
         }, $hostPatterns);
         // we need to reset trusted hosts on trusted host patterns change
         self::$trustedHosts = array();
diff --git a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
index a1a123426b..9d2e6e7a67 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -1601,7 +1601,7 @@ class RequestTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('evil.com', $request->getHost());
 
         // add a trusted domain and all its subdomains
-        Request::setTrustedHosts(array('.*\.?trusted.com$'));
+        Request::setTrustedHosts(array('^([a-z]{9}\.)?trusted\.com$'));
 
         // untrusted host
         $request->headers->set('host', 'evil.com');