diff --git a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
index cf648dfe9d54..6c9a995e9a31 100644
--- a/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
+++ b/src/Symfony/Component/HttpFoundation/BinaryFileResponse.php
@@ -227,13 +227,18 @@ public function prepare(Request $request)
 
                         if (substr($path, 0, \strlen($pathPrefix)) === $pathPrefix) {
                             $path = $location.substr($path, \strlen($pathPrefix));
+                            // Only set X-Accel-Redirect header if a valid URI can be produced
+                            // as nginx does not serve arbitrary file paths.
+                            $this->headers->set($type, $path);
+                            $this->maxlen = 0;
                             break;
                         }
                     }
                 }
+            } else {
+                $this->headers->set($type, $path);
+                $this->maxlen = 0;
             }
-            $this->headers->set($type, $path);
-            $this->maxlen = 0;
         } elseif ($request->headers->has('Range')) {
             // Process the range headers.
             if (!$request->headers->has('If-Range') || $this->hasValidIfRangeHeader($request->headers->get('If-Range'))) {
diff --git a/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php b/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
index c89f20d05a49..853b4bb3dfe1 100644
--- a/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
+++ b/src/Symfony/Component/HttpFoundation/Tests/BinaryFileResponseTest.php
@@ -338,6 +338,7 @@ public function getSampleXAccelMappings()
         return [
             ['/var/www/var/www/files/foo.txt', '/var/www/=/files/', '/files/var/www/files/foo.txt'],
             ['/home/foo/bar.txt', '/var/www/=/files/,/home/foo/=/baz/', '/baz/bar.txt'],
+            ['/tmp/bar.txt', '"/var/www/"="/files/", "/home/Foo/"="/baz/"', null],
         ];
     }