diff --git a/openpgp/modules/openpgp.py b/openpgp/modules/openpgp.py
index b39c0d7..4f2b0ac 100644
--- a/openpgp/modules/openpgp.py
+++ b/openpgp/modules/openpgp.py
@@ -109,9 +109,9 @@ class ContactData:
 
     @property
     def userid(self):
-        if self._jid is None:
+        if self.jid is None:
             raise ValueError('JID not set')
-        return 'xmpp:%s' % self._jid
+        return 'xmpp:%s' % self.jid
 
     @property
     def default_trust(self):
@@ -185,7 +185,7 @@ class ContactData:
         try:
             keydata = self._key_store[fingerprint]
         except KeyError:
-            log.warning('Set public key on unknown fingerprint',
+            log.warning('Set public key on unknown fingerprint: %s %s',
                         self.jid, fingerprint)
         else:
             keydata.has_pubkey = True
diff --git a/openpgp/modules/pgp_keylist.py b/openpgp/modules/pgp_keylist.py
index 02a1398..e4e5b47 100644
--- a/openpgp/modules/pgp_keylist.py
+++ b/openpgp/modules/pgp_keylist.py
@@ -95,7 +95,7 @@ class PGPKeylist(AbstractPEPModule):
             else:
                 timestamp = parse_datetime(date, epoch=True)
                 if timestamp is None:
-                    raise StanzaMalformed('Invalid date timestamp: %s', date)
+                    raise StanzaMalformed('Invalid date timestamp: %s' % date)
 
             keylist.append(Key(attrs['v4-fingerprint'], int(timestamp)))
 
diff --git a/openpgp/modules/util.py b/openpgp/modules/util.py
index eb5c2c7..7934819 100644
--- a/openpgp/modules/util.py
+++ b/openpgp/modules/util.py
@@ -207,7 +207,7 @@ def get_info_message():
     return '[This message is *encrypted* with OpenPGP (See :XEP:`0373`]'
 
 
-def add_additional_data(data, fingerprint, trust):
+def add_additional_data(data, fingerprint):
     data['encrypted'] = {'name': ENCRYPTION_NAME,
                          'fingerprint': fingerprint}