diff --git a/omemo/backend/devices.py b/omemo/backend/devices.py
index 651c693..3790785 100644
--- a/omemo/backend/devices.py
+++ b/omemo/backend/devices.py
@@ -82,8 +82,9 @@ class DeviceManager:
     def get_devices_for_encryption(self, jid):
         devices_for_encryption = []
 
-        # TODO:
-        if app.contacts.get_groupchat_contact(self._account, jid) is not None:
+        client = app.get_client(self._account)
+        contact = client.get_module('Contacts').get_contact(jid)
+        if contact.is_groupchat:
             devices_for_encryption = self._get_devices_for_muc_encryption(jid)
         else:
             devices_for_encryption = self._get_devices_for_encryption(jid)
diff --git a/omemo/modules/omemo.py b/omemo/modules/omemo.py
index 71166cb..5d69002 100644
--- a/omemo/modules/omemo.py
+++ b/omemo/modules/omemo.py
@@ -21,7 +21,6 @@ from pathlib import Path
 
 from nbxmpp.namespaces import Namespace
 from nbxmpp.protocol import NodeProcessed
-from nbxmpp.protocol import JID
 from nbxmpp.errors import StanzaError
 from nbxmpp.const import PresenceType
 from nbxmpp.const import Affiliation
@@ -257,16 +256,14 @@ class OMEMO(BaseModule):
                                                'trust': GajimTrust[trust.name]})
 
     def _process_muc_message(self, properties):
-        room_jid = properties.jid.bare
         resource = properties.jid.resource
         if properties.muc_ofrom is not None:
             # History Message from MUC
             return properties.muc_ofrom.bare
 
-        # TODO:
-        contact = app.contacts.get_gc_contact(self._account, room_jid, resource)
-        if contact is not None:
-            return JID.from_string(contact.jid).bare
+        contact = self._con.get_module('Contacts').get_contact(properties.jid)
+        if contact.real_jid is not None:
+            return contact.real_jid.bare
 
         self._log.info('Groupchat: Last resort trying to find SID in DB')
         from_jid = self.backend.storage.getJidFromDevice(properties.omemo.sid)