diff --git a/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php b/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
index bf30fe8124..ecde40c77e 100644
--- a/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
+++ b/src/Symfony/Component/HttpFoundation/File/MimeType/FileBinaryMimeTypeGuesser.php
@@ -62,7 +62,7 @@ class FileBinaryMimeTypeGuesser implements MimeTypeGuesserInterface
 
         $type = trim(ob_get_clean());
 
-        if (!preg_match('#^([a-z0-9\-]+/[a-z0-9\-]+)#i', $type, $match)) {
+        if (!preg_match('#^([a-z0-9\-]+/[a-z0-9\-\.]+)#i', $type, $match)) {
             // it's not a type, but an error message
             return null;
         }