diff --git a/src/Symfony/Component/HttpFoundation/Request.php b/src/Symfony/Component/HttpFoundation/Request.php
index ecdcdbc25a..e1309d477b 100644
--- a/src/Symfony/Component/HttpFoundation/Request.php
+++ b/src/Symfony/Component/HttpFoundation/Request.php
@@ -581,7 +581,7 @@ class Request
     public static function setTrustedHosts(array $hostPatterns)
     {
         self::$trustedHostPatterns = array_map(function ($hostPattern) {
-            return sprintf('#%s#i', $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 0c5451dfd6..688a7c714a 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/RequestTest.php
@@ -18,6 +18,11 @@ use Symfony\Component\HttpFoundation\Request;
 
 class RequestTest extends TestCase
 {
+    protected function tearDown()
+    {
+        Request::setTrustedHosts(array());
+    }
+
     public function testInitialize()
     {
         $request = new Request();
@@ -1871,9 +1876,15 @@ class RequestTest extends TestCase
 
         $request->headers->set('host', 'subdomain.trusted.com');
         $this->assertEquals('subdomain.trusted.com', $request->getHost());
+    }
 
-        // reset request for following tests
-        Request::setTrustedHosts(array());
+    public function testSetTrustedHostsDoesNotBreakOnSpecialCharacters()
+    {
+        Request::setTrustedHosts(array('localhost(\.local){0,1}#,example.com', 'localhost'));
+
+        $request = Request::create('/');
+        $request->headers->set('host', 'localhost');
+        $this->assertSame('localhost', $request->getHost());
     }
 
     public function testFactory()