diff --git a/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeExtensionGuesser.php b/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeExtensionGuesser.php
index 422556195c..75eeefbf5d 100644
--- a/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeExtensionGuesser.php
+++ b/src/Symfony/Component/HttpFoundation/File/MimeType/MimeTypeExtensionGuesser.php
@@ -723,6 +723,7 @@ class MimeTypeExtensionGuesser implements ExtensionGuesserInterface
         'text/plain' => 'txt',
         'text/prs.lines.tag' => 'dsc',
         'text/richtext' => 'rtx',
+        'text/rtf' => 'rtf',
         'text/sgml' => 'sgml',
         'text/tab-separated-values' => 'tsv',
         'text/troff' => 't',