edit

lib/Store/Core.php

@@ -628,8 +628,8 @@ class Core
 			'x-world/x-vrml' => 'flr',
 			'application/x-rar' => 'rar',
 			'application/vnd.android.package-archive' => 'apk',
-			'audio/webm' => 'mp3',
-			'video/webm' => 'mp4',
+			'audio/webm' => 'webm',
+			'video/webm' => 'webm',
 		);
 
 		if (isset($config[$mine])) {