diff --git a/lib/Cake/Network/CakeResponse.php b/lib/Cake/Network/CakeResponse.php
index 2f60667fe..8ee08b2a1 100644
--- a/lib/Cake/Network/CakeResponse.php
+++ b/lib/Cake/Network/CakeResponse.php
@@ -300,6 +300,7 @@ class CakeResponse {
 		'webapp' => 'application/x-web-app-manifest+json',
 		'vcf' => 'text/x-vcard',
 		'vtt' => 'text/vtt',
+		'mkv' => 'video/x-matroska',
 	);
 
 /**