diff --git a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
index 490726dadf799..202eee578bfc2 100644
--- a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
+++ b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
@@ -161,17 +161,7 @@ public function setContentDisposition($disposition, $filename = '', $filenameFal
         }
 
         if ('' === $filenameFallback && (!preg_match('/^[\x20-\x7e]*$/', $filename) || false !== strpos($filename, '%'))) {
-            $encoding = mb_detect_encoding($filename, null, true);
-
-            for ($i = 0; $i < mb_strlen($filename, $encoding); ++$i) {
-                $char = mb_substr($filename, $i, 1, $encoding);
-
-                if ('%' === $char || ord($char) < 32 || ord($char) > 126) {
-                    $filenameFallback .= '_';
-                } else {
-                    $filenameFallback .= $char;
-                }
-            }
+            $filenameFallback = preg_replace('/[^\x20-\x7e]|%/u', '_', $filename);
         }
 
         $dispositionHeader = $this->headers->makeDisposition($disposition, $filename, $filenameFallback);
diff --git a/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
index ac6c3288aebc3..cd5369811d5fe 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
@@ -36,7 +36,13 @@ public function testConstruction()
 
     public function testConstructWithNonAsciiFilename()
     {
-        new BinaryFileResponse(__DIR__.'/Fixtures/föö.html', 200, array(), true, 'attachment');
+        touch(sys_get_temp_dir().'/fööö.html');
+
+        $response = new BinaryFileResponse(sys_get_temp_dir().'/fööö.html', 200, array(), true, 'attachment');
+
+        $this->assertSame('fööö.html', $response->getFile()->getFilename());
+
+        @unlink(sys_get_temp_dir().'/fööö.html');
     }
 
     /**