diff --git a/slixmpp/plugins/__init__.py b/slixmpp/plugins/__init__.py
index c21cc343..a89b10f6 100644
--- a/slixmpp/plugins/__init__.py
+++ b/slixmpp/plugins/__init__.py
@@ -86,6 +86,6 @@ __all__ = [
     'xep_0325',  # IoT Systems Control
     'xep_0332',  # HTTP Over XMPP Transport
     'xep_0377',  # Spam reporting
+    'xep_0421',  # Anonymous unique occupant identifiers for MUCs
     'xep_0444',  # Message Reactions
-    'protoxep_occupantid',  # https://dino.im/xeps/occupant-id.html
 ]
diff --git a/slixmpp/plugins/protoxep_occupantid/__init__.py b/slixmpp/plugins/protoxep_occupantid/__init__.py
deleted file mode 100644
index 1bd374b6..00000000
--- a/slixmpp/plugins/protoxep_occupantid/__init__.py
+++ /dev/null
@@ -1,12 +0,0 @@
-"""
-    Slixmpp: The Slick XMPP Library
-    Copyright (C) 2019 Mathieu Pasquet
-    This file is part of Slixmpp.
-
-    See the file LICENSE for copying permission.
-"""
-from slixmpp.plugins.base import register_plugin
-from slixmpp.plugins.protoxep_occupantid.occupantid import XEP_OccupantID
-from slixmpp.plugins.protoxep_occupantid.stanza import OccupantID
-
-register_plugin(XEP_OccupantID)
diff --git a/slixmpp/plugins/protoxep_occupantid/occupantid.py b/slixmpp/plugins/protoxep_occupantid/occupantid.py
deleted file mode 100644
index 7f4a9d4a..00000000
--- a/slixmpp/plugins/protoxep_occupantid/occupantid.py
+++ /dev/null
@@ -1,23 +0,0 @@
-"""
-    Slixmpp: The Slick XMPP Library
-    Copyright (C) 2019 Mathieu Pasquet
-    This file is part of Slixmpp.
-
-    See the file LICENSE for copying permission.
-"""
-from slixmpp.plugins import BasePlugin
-from slixmpp.stanza import Message, Presence
-from slixmpp.xmlstream import register_stanza_plugin
-
-from slixmpp.plugins.protoxep_occupantid import stanza
-
-
-class XEP_OccupantID(BasePlugin):
-    name = 'protoxep_occupantid'
-    description = 'XEP-XXXX: Anonymous unique occupant identifiers for MUCs'
-    dependencies = set()
-    stanza = stanza
-
-    def plugin_init(self):
-        register_stanza_plugin(Message, stanza.OccupantID)
-        register_stanza_plugin(Presence, stanza.OccupantID)
diff --git a/slixmpp/plugins/protoxep_occupantid/stanza.py b/slixmpp/plugins/protoxep_occupantid/stanza.py
deleted file mode 100644
index e5853111..00000000
--- a/slixmpp/plugins/protoxep_occupantid/stanza.py
+++ /dev/null
@@ -1,16 +0,0 @@
-"""
-    Slixmpp: The Slick XMPP Library
-    Copyright (C) 2019 Mathieu Pasquet
-    This file is part of Slixmpp.
-
-    See the file LICENSE for copying permission.
-"""
-
-from slixmpp.xmlstream import ElementBase
-
-
-class OccupantID(ElementBase):
-    name = 'occupant-id'
-    plugin_attrib = 'occupant-id'
-    namespace = 'urn:xmpp:occupant-id:0'
-    interfaces = {'id'}
diff --git a/slixmpp/plugins/xep_0421/occupant_id.py b/slixmpp/plugins/xep_0421/occupant_id.py
index 116bf2d9..4ee27a09 100644
--- a/slixmpp/plugins/xep_0421/occupant_id.py
+++ b/slixmpp/plugins/xep_0421/occupant_id.py
@@ -6,7 +6,7 @@
     See the file LICENSE for copying permission.
 """
 
-from slixmpp import JID, Message
+from slixmpp import JID, Message, Presence
 from slixmpp.plugins import BasePlugin
 from slixmpp.xmlstream import register_stanza_plugin
 from slixmpp.plugins.xep_0421 import stanza
@@ -25,6 +25,7 @@ class XEP_0421(BasePlugin):
     def plugin_init(self) -> None:
         # XXX: This should be MucMessage. Someday..
         register_stanza_plugin(Message, OccupantId)
+        register_stanza_plugin(Presence, OccupantId)
 
     async def has_feature(self, jid: JID) -> bool:
         info = await self.xmpp['xep_0030'].get_info(jid)
diff --git a/slixmpp/plugins/xep_0421/stanza.py b/slixmpp/plugins/xep_0421/stanza.py
index 0cb93959..ab1128d6 100644
--- a/slixmpp/plugins/xep_0421/stanza.py
+++ b/slixmpp/plugins/xep_0421/stanza.py
@@ -36,5 +36,6 @@ class OccupantId(ElementBase):
     '''
 
     name = 'occupant-id'
+    plugin_attrib = 'occupant-id'
     namespace = NS
     interface = {'id'}