diff --git a/sylk/extensions.py b/sylk/extensions.py
index 715aac7..1f4cf95 100644
--- a/sylk/extensions.py
+++ b/sylk/extensions.py
@@ -1,81 +1,81 @@
 # Copyright (C) 2010-2011 AG Projects. See LICENSE for details.
 #
 
 import random
 
 from datetime import datetime
 
 from msrplib.protocol import URI
 from msrplib.session import contains_mime_type
 from sipsimple.account import AccountManager
 from sipsimple.core import SDPAttribute
 from sipsimple.payloads.iscomposing import IsComposingDocument, IsComposingMessage, State, LastActive, Refresh, ContentType
 from sipsimple.streams import MediaStreamRegistry
 from sipsimple.streams.applications.chat import CPIMMessage
 from sipsimple.streams.msrp import ChatStream as _ChatStream, ChatStreamError, MSRPStreamBase
 
 from sylk.configuration import SIPConfig
 
 
 # We need to match on the only account that will be available
 def _always_find_default_account(self, contact_uri):
     return self.default_account
 AccountManager.find_account = _always_find_default_account
 
 
 # We need to be able to set the local identity in the message CPIM envelope
 # so that messages appear to be coming from the users themselves, instead of
 # just seeying the server identity
 registry = MediaStreamRegistry()
 for stream_type in registry.stream_types[:]:
     if stream_type is _ChatStream:
         registry.stream_types.remove(stream_type)
         break
 del registry
 
 class ChatStream(_ChatStream):
     accept_types = ['message/cpim']
     accept_wrapped_types = ['*']
-    chatroom_capabilities = ['private-messages', 'screen-sharing']
+    chatroom_capabilities = ['private-messages', 'com.ag-projects.screen-sharing']
 
     @property
     def local_uri(self):
         return URI(host=SIPConfig.local_ip, port=0, use_tls=self.transport=='tls', credentials=self.account.tls_credentials)
 
     def _create_local_media(self, uri_path):
         local_media = MSRPStreamBase._create_local_media(self, uri_path)
         if self.session.local_focus and self.chatroom_capabilities:
             local_media.attributes.append(SDPAttribute('chatroom', ' '.join(self.chatroom_capabilities)))
         return local_media
 
     def send_message(self, content, content_type='text/plain', local_identity=None, recipients=None, courtesy_recipients=None, subject=None, timestamp=None, required=None, additional_headers=None):
         if self.direction=='recvonly':
             raise ChatStreamError('Cannot send message on recvonly stream')
         message_id = '%x' % random.getrandbits(64)
         if not contains_mime_type(self.accept_wrapped_types, content_type):
             raise ChatStreamError('Invalid content_type for outgoing message: %r' % content_type)
         if not recipients:
             recipients = [self.remote_identity]
         if timestamp is None:
             timestamp = datetime.now()
         # Only use CPIM, it's the only type we accept
         msg = CPIMMessage(content, content_type, sender=local_identity or self.local_identity, recipients=recipients, courtesy_recipients=courtesy_recipients,
                             subject=subject, timestamp=timestamp, required=required, additional_headers=additional_headers)
         self._enqueue_message(message_id, str(msg), 'message/cpim', failure_report='yes', success_report='yes', notify_progress=True)
         return message_id
 
     def send_composing_indication(self, state, refresh, last_active=None, recipients=None, local_identity=None):
         if self.direction == 'recvonly':
             raise ChatStreamError('Cannot send message on recvonly stream')
         if state not in ('active', 'idle'):
             raise ValueError('Invalid value for composing indication state')
         message_id = '%x' % random.getrandbits(64)
         content = IsComposingMessage(state=State(state), refresh=Refresh(refresh), last_active=LastActive(last_active or datetime.now()), content_type=ContentType('text')).toxml()
         if recipients is None:
             recipients = [self.remote_identity]
         # Only use CPIM, it's the only type we accept
         msg = CPIMMessage(content, IsComposingDocument.content_type, sender=local_identity or self.local_identity, recipients=recipients, timestamp=datetime.now())
         self._enqueue_message(message_id, str(msg), 'message/cpim', failure_report='partial', success_report='no')
         return message_id