diff --git a/gajim/common/caps_cache.py b/gajim/common/caps_cache.py
index 5fdf53490..e96caacca 100644
--- a/gajim/common/caps_cache.py
+++ b/gajim/common/caps_cache.py
@@ -449,7 +449,8 @@ class MucCapsCache:
                 features.append(child.getAttr('var'))
             elif child.getName() == 'x':
                 if child.getNamespace() == nbxmpp.NS_DATA:
-                    data.append(nbxmpp.DataForm(node=child))
+                    from gajim.common import dataforms
+                    data.append(dataforms.ExtendForm(node=child))
 
         if nbxmpp.NS_MUC not in features:
             # Not a MUC, dont cache info
@@ -483,3 +484,16 @@ class MucCapsCache:
                 return nbxmpp.NS_MAM_1
         except (KeyError, AttributeError):
             return
+
+    def is_subject_change_allowed(self, jid, affiliation):
+        allowed = True
+        if affiliation in ('owner, admin'):
+            return allowed
+
+        if jid in self.cache:
+            for form in self.cache[jid].data:
+                try:
+                    allowed = form['muc#roominfo_changesubject'].value
+                except KeyError:
+                    pass
+        return allowed
diff --git a/gajim/common/connection_handlers.py b/gajim/common/connection_handlers.py
index f666b3c6a..2cc47d1ab 100644
--- a/gajim/common/connection_handlers.py
+++ b/gajim/common/connection_handlers.py
@@ -101,8 +101,8 @@ class ConnectionDisco:
         id_ = self._discover(nbxmpp.NS_DISCO_INFO, jid, node, id_prefix)
         self.disco_info_ids.append(id_)
 
-    def discoverMUC(self, jid, callback):
-        if muc_caps_cache.is_cached(jid):
+    def discoverMUC(self, jid, callback, update=False):
+        if muc_caps_cache.is_cached(jid) and not update:
             callback()
             return
         disco_info = nbxmpp.Iq(typ='get', to=jid, queryNS=nbxmpp.NS_DISCO_INFO)
diff --git a/gajim/groupchat_control.py b/gajim/groupchat_control.py
index ee6d4eb30..31e61ded9 100644
--- a/gajim/groupchat_control.py
+++ b/gajim/groupchat_control.py
@@ -603,9 +603,12 @@ class GroupchatControl(ChatControlBase):
             online and role == 'visitor')
 
         # Change Subject
-        # Get this from Room Disco
+        subject = False
+        if contact is not None:
+            subject = muc_caps_cache.is_subject_change_allowed(
+                self.room_jid, contact.affiliation)
         win.lookup_action('change-subject-' + self.control_id).set_enabled(
-            online)
+            online and subject)
 
         # Change Nick
         win.lookup_action('change-nick-' + self.control_id).set_enabled(
@@ -1521,7 +1524,9 @@ class GroupchatControl(ChatControlBase):
             changes.append(_('Room now does not show unavailable members'))
         if '104' in obj.status_code:
             changes.append(_('A setting not related to privacy has been '
-                'changed'))
+                             'changed'))
+            app.connections[self.account].discoverMUC(
+                self.room_jid, self.update_actions, update=True)
         if '170' in obj.status_code:
             # Can be a presence (see chg_contact_status in groupchat_control.py)
             changes.append(_('Room logging is now enabled'))