diff --git a/pandoralocal/server.py b/pandoralocal/server.py
index ba11a14..26e436b 100644
--- a/pandoralocal/server.py
+++ b/pandoralocal/server.py
@@ -155,7 +155,7 @@ class Server(Resource):
             if path:
                 print itemId, filename, 'use', path
                 request.headers['Access-Control-Allow-Origin'] = '*'
-                f = File(path)
+                f = File(path, 'video/webm')
                 f.isLeaf = True
                 return f
             else: