diff --git a/federation/entities/activitypub/entities.py b/federation/entities/activitypub/entities.py
index 00cf521..cb3f00e 100644
--- a/federation/entities/activitypub/entities.py
+++ b/federation/entities/activitypub/entities.py
@@ -10,7 +10,7 @@ from federation.entities.activitypub.constants import (
 from federation.entities.activitypub.enums import ActorType, ObjectType, ActivityType
 from federation.entities.activitypub.mixins import ActivitypubObjectMixin, ActivitypubActorMixin
 from federation.entities.activitypub.objects import ImageObject
-from federation.entities.base import Profile, Post, Follow, Accept
+from federation.entities.base import Profile, Post, Follow, Accept, Comment
 from federation.outbound import handle_send
 from federation.types import UserType
 from federation.utils.text import with_slash
@@ -138,6 +138,13 @@ class ActivitypubPost(ActivitypubObjectMixin, Post):
         return as2
 
 
+class ActivitypubComment(ActivitypubPost, Comment):
+    def to_as2(self) -> Dict:
+        as2 = super().to_as2()
+        as2["object"]["inReplyTo"] = self.target_id
+        return as2
+
+
 class ActivitypubProfile(ActivitypubActorMixin, Profile):
     _type = ActorType.PERSON.value
     public = True
diff --git a/federation/entities/activitypub/mappers.py b/federation/entities/activitypub/mappers.py
index be991f0..8c73e83 100644
--- a/federation/entities/activitypub/mappers.py
+++ b/federation/entities/activitypub/mappers.py
@@ -3,7 +3,7 @@ from typing import List, Callable, Dict, Union
 
 from federation.entities.activitypub.constants import NAMESPACE_PUBLIC
 from federation.entities.activitypub.entities import (
-    ActivitypubFollow, ActivitypubProfile, ActivitypubAccept, ActivitypubPost)
+    ActivitypubFollow, ActivitypubProfile, ActivitypubAccept, ActivitypubPost, ActivitypubComment)
 from federation.entities.base import Follow, Profile, Accept, Post
 from federation.entities.mixins import BaseEntity
 from federation.types import UserType
@@ -28,10 +28,12 @@ def element_to_objects(payload: Dict) -> List:
     """
     entities = []
     if isinstance(payload.get('object'), dict) and payload["object"].get('type'):
-        as2_type = payload["object"]["type"]
+        if payload["object"]["type"] == "Note" and payload["object"].get("inReplyTo"):
+            cls = ActivitypubComment
+        else:
+            cls = MAPPINGS.get(payload["object"]["type"])
     else:
-        as2_type = payload.get('type')
-    cls = MAPPINGS.get(as2_type)
+        cls = MAPPINGS.get(payload.get('type'))
     if not cls:
         return []
 
@@ -151,6 +153,8 @@ def transform_attribute(key: str, value: Union[str, Dict, int], transformed: Dic
         transformed["inboxes"]["private"] = value
         if not transformed["inboxes"]["public"]:
             transformed["inboxes"]["public"] = value
+    elif key == "inReplyTo":
+        transformed["target_id"] = value
     elif key == "name":
         transformed["name"] = value
     elif key == "object":
diff --git a/federation/tests/entities/activitypub/test_mappers.py b/federation/tests/entities/activitypub/test_mappers.py
index 6858247..fdc3414 100644
--- a/federation/tests/entities/activitypub/test_mappers.py
+++ b/federation/tests/entities/activitypub/test_mappers.py
@@ -3,11 +3,12 @@ from unittest.mock import patch
 import pytest
 
 from federation.entities.activitypub.entities import (
-    ActivitypubFollow, ActivitypubAccept, ActivitypubProfile, ActivitypubPost)
+    ActivitypubFollow, ActivitypubAccept, ActivitypubProfile, ActivitypubPost, ActivitypubComment)
 from federation.entities.activitypub.mappers import message_to_objects, get_outbound_entity
-from federation.entities.base import Accept, Follow, Profile, Post
+from federation.entities.base import Accept, Follow, Profile, Post, Comment
 from federation.tests.fixtures.payloads import (
-    ACTIVITYPUB_FOLLOW, ACTIVITYPUB_PROFILE, ACTIVITYPUB_PROFILE_INVALID, ACTIVITYPUB_UNDO_FOLLOW, ACTIVITYPUB_POST)
+    ACTIVITYPUB_FOLLOW, ACTIVITYPUB_PROFILE, ACTIVITYPUB_PROFILE_INVALID, ACTIVITYPUB_UNDO_FOLLOW, ACTIVITYPUB_POST,
+    ACTIVITYPUB_COMMENT)
 
 
 class TestActivitypubEntityMappersReceive:
@@ -53,7 +54,8 @@ class TestActivitypubEntityMappersReceive:
                                    'class="u-url mention">@<span>jaywink</span></a></span> boom</p>'
         assert post.id == "https://diaspodon.fr/users/jaywink/statuses/102356911717767237"
         assert post.actor_id == "https://diaspodon.fr/users/jaywink"
-        assert post.public == True
+        assert post.public is True
+        assert getattr(post, "target_id", None) is None
 
     @pytest.mark.skip
     def test_message_to_objects_post_with_photos(self):
@@ -75,24 +77,18 @@ class TestActivitypubEntityMappersReceive:
         assert photo.public == False
         assert photo.created_at == datetime(2011, 7, 20, 1, 36, 7)
 
-    @pytest.mark.skip
-    def test_message_to_objects_comment(self, mock_validate):
-        entities = message_to_objects(DIASPORA_POST_COMMENT, "alice@alice.diaspora.example.org",
-                                      sender_key_fetcher=Mock())
+    def test_message_to_objects_comment(self):
+        entities = message_to_objects(ACTIVITYPUB_COMMENT, "https://diaspodon.fr/users/jaywink")
         assert len(entities) == 1
         comment = entities[0]
-        assert isinstance(comment, DiasporaComment)
+        assert isinstance(comment, ActivitypubComment)
         assert isinstance(comment, Comment)
-        assert comment.target_guid == "((parent_guidparent_guidparent_guidparent_guid))"
-        assert comment.guid == "((guidguidguidguidguidguid))"
-        assert comment.handle == "alice@alice.diaspora.example.org"
-        assert comment.participation == "comment"
-        assert comment.raw_content == "((text))"
-        assert comment.signature == "((signature))"
-        assert comment._xml_tags == [
-            "guid", "parent_guid", "text", "author",
-        ]
-        mock_validate.assert_called_once_with()
+        assert comment.raw_content == '<p><span class="h-card"><a href="https://dev.jasonrobinson.me/u/jaywink/" ' \
+                                      'class="u-url mention">@<span>jaywink</span></a></span> boom</p>'
+        assert comment.id == "https://diaspodon.fr/users/jaywink/statuses/102356911717767237"
+        assert comment.actor_id == "https://diaspodon.fr/users/jaywink"
+        assert comment.public is True
+        assert comment.target_id == "https://dev.jasonrobinson.me/content/653bad70-41b3-42c9-89cb-c4ee587e68e4/"
 
     @pytest.mark.skip
     def test_message_to_objects_like(self, mock_validate):
diff --git a/federation/tests/fixtures/payloads/activitypub.py b/federation/tests/fixtures/payloads/activitypub.py
index c99546a..0fa6a71 100644
--- a/federation/tests/fixtures/payloads/activitypub.py
+++ b/federation/tests/fixtures/payloads/activitypub.py
@@ -1,3 +1,53 @@
+ACTIVITYPUB_COMMENT = {
+  '@context': ['https://www.w3.org/ns/activitystreams',
+  {'ostatus': 'http://ostatus.org#',
+   'atomUri': 'ostatus:atomUri',
+   'inReplyToAtomUri': 'ostatus:inReplyToAtomUri',
+   'conversation': 'ostatus:conversation',
+   'sensitive': 'as:sensitive',
+   'Hashtag': 'as:Hashtag',
+   'toot': 'http://joinmastodon.org/ns#',
+   'Emoji': 'toot:Emoji',
+   'focalPoint': {'@container': '@list', '@id': 'toot:focalPoint'},
+   'blurhash': 'toot:blurhash'}],
+ 'id': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237/activity',
+ 'type': 'Create',
+ 'actor': 'https://diaspodon.fr/users/jaywink',
+ 'published': '2019-06-29T21:08:45Z',
+ 'to': ['https://www.w3.org/ns/activitystreams#Public'],
+ 'cc': ['https://diaspodon.fr/users/jaywink/followers',
+  'https://dev.jasonrobinson.me/p/d4574854-a5d7-42be-bfac-f70c16fcaa97/'],
+ 'object': {'id': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237',
+  'type': 'Note',
+  'summary': None,
+  'inReplyTo': 'https://dev.jasonrobinson.me/content/653bad70-41b3-42c9-89cb-c4ee587e68e4/',
+  'published': '2019-06-29T21:08:45Z',
+  'url': 'https://diaspodon.fr/@jaywink/102356911717767237',
+  'attributedTo': 'https://diaspodon.fr/users/jaywink',
+  'to': ['https://www.w3.org/ns/activitystreams#Public'],
+  'cc': ['https://diaspodon.fr/users/jaywink/followers',
+   'https://dev.jasonrobinson.me/p/d4574854-a5d7-42be-bfac-f70c16fcaa97/'],
+  'sensitive': False,
+  'atomUri': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237',
+  'inReplyToAtomUri': 'https://dev.jasonrobinson.me/content/653bad70-41b3-42c9-89cb-c4ee587e68e4/',
+  'conversation': 'tag:diaspodon.fr,2019-06-28:objectId=2347687:objectType=Conversation',
+  'content': '<p><span class="h-card"><a href="https://dev.jasonrobinson.me/u/jaywink/" class="u-url mention">@<span>jaywink</span></a></span> boom</p>',
+  'contentMap': {'en': '<p><span class="h-card"><a href="https://dev.jasonrobinson.me/u/jaywink/" class="u-url mention">@<span>jaywink</span></a></span> boom</p>'},
+  'attachment': [],
+  'tag': [{'type': 'Mention',
+    'href': 'https://dev.jasonrobinson.me/p/d4574854-a5d7-42be-bfac-f70c16fcaa97/',
+    'name': '@jaywink@dev.jasonrobinson.me'}],
+  'replies': {'id': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237/replies',
+   'type': 'Collection',
+   'first': {'type': 'CollectionPage',
+    'partOf': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237/replies',
+    'items': []}}},
+ 'signature': {'type': 'RsaSignature2017',
+  'creator': 'https://diaspodon.fr/users/jaywink#main-key',
+  'created': '2019-06-29T21:08:45Z',
+  'signatureValue': 'SjDACS7Z/Cb1SEC3AtxEokID5SHAYl7kpys/hhmaRbpXuFKCxfj2P9BmH8QhLnuam3sENZlrnBOcB5NlcBhIfwo/Xh242RZBmPQf+edTVYVCe1j19dihcftNCHtnqAcKwp/51dNM/OlKu2730FrwvOUXVIPtB7iVqkseO9TRzDYIDj+zBTksnR/NAYtq6SUpmefXfON0uW3N3Uq6PGfExJaS+aeqRf8cPGkZFSIUQZwOLXbIpb7BFjJ1+y1OMOAJueqvikUprAit3v6BiNWurAvSQpC7WWMFUKyA79/xtkO9kIPA/Q4C9ryqdzxZJ0jDhXiaIIQj2JZfIADdjLZHJA=='}
+}
+
 ACTIVITYPUB_FOLLOW = {
   "@context": [
     "https://www.w3.org/ns/activitystreams",
@@ -132,7 +182,7 @@ ACTIVITYPUB_POST = {
  'object': {'id': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237',
   'type': 'Note',
   'summary': None,
-  'inReplyTo': 'https://dev.jasonrobinson.me/content/653bad70-41b3-42c9-89cb-c4ee587e68e4/',
+  'inReplyTo': None,
   'published': '2019-06-29T21:08:45Z',
   'url': 'https://diaspodon.fr/@jaywink/102356911717767237',
   'attributedTo': 'https://diaspodon.fr/users/jaywink',
@@ -141,7 +191,7 @@ ACTIVITYPUB_POST = {
    'https://dev.jasonrobinson.me/p/d4574854-a5d7-42be-bfac-f70c16fcaa97/'],
   'sensitive': False,
   'atomUri': 'https://diaspodon.fr/users/jaywink/statuses/102356911717767237',
-  'inReplyToAtomUri': 'https://dev.jasonrobinson.me/content/653bad70-41b3-42c9-89cb-c4ee587e68e4/',
+  'inReplyToAtomUri': None,
   'conversation': 'tag:diaspodon.fr,2019-06-28:objectId=2347687:objectType=Conversation',
   'content': '<p><span class="h-card"><a href="https://dev.jasonrobinson.me/u/jaywink/" class="u-url mention">@<span>jaywink</span></a></span> boom</p>',
   'contentMap': {'en': '<p><span class="h-card"><a href="https://dev.jasonrobinson.me/u/jaywink/" class="u-url mention">@<span>jaywink</span></a></span> boom</p>'},