diff --git a/protocol.py b/protocol.py
index eec10ecf..0c18a819 100644
--- a/protocol.py
+++ b/protocol.py
@@ -723,7 +723,10 @@ def translate(elem, field, fn):
                     translate(tag, 'url', translate_user_id)
             for att in as1.get_objects(o, 'attachments'):
                 translate(att, 'id', translate_object_id)
-                translate(att, 'url', translate_object_id)
+                url = att.get('url')
+                if url and not att.get('id'):
+                    from_cls = Protocol.for_id(url)
+                    att['id'] = translate_object_id(from_=from_cls, to=to_cls, id=url)
 
         outer_obj = util.trim_nulls(outer_obj)
         if outer_obj.get('object', {}).keys() == {'id'}:
diff --git a/tests/test_activitypub.py b/tests/test_activitypub.py
index bfcd9bde..f433fdac 100644
--- a/tests/test_activitypub.py
+++ b/tests/test_activitypub.py
@@ -2557,6 +2557,35 @@ def test_convert_adds_context_to_as2(self):
             'object': ACTOR,
         }, ActivityPub.convert(obj))
 
+    def test_convert_quote_post(self):
+        obj = Object(id='at://did:alice/app.bsky.feed.post/123', bsky={
+            '$type': 'app.bsky.feed.post',
+            'text': 'foo bar',
+            'embed': {
+                '$type': 'app.bsky.embed.record',
+                'record': {
+                    'cid': 'bafyreih...',
+                    'uri': 'at://did:bob/app.bsky.feed.post/456'
+                }
+            },
+        })
+
+        self.assert_equals({
+            'type': 'Note',
+            'id': 'https://bsky.brid.gy/convert/ap/at://did:alice/app.bsky.feed.post/123',
+            'url': 'http://localhost/r/https://bsky.app/profile/did:alice/post/123',
+            'content': '<p>foo bar<br><br>RE: <a href="https://bsky.app/profile/did:bob/post/456">https://bsky.app/profile/did:bob/post/456</a></p>',
+            'attributedTo': 'did:alice',
+            '_misskey_quote': 'https://bsky.brid.gy/convert/ap/at://did:bob/app.bsky.feed.post/456',
+            'quoteUrl': 'https://bsky.brid.gy/convert/ap/at://did:bob/app.bsky.feed.post/456',
+            'tag': [{
+                'type': 'Link',
+                'mediaType': as2.CONTENT_TYPE_LD_PROFILE,
+                'href': 'https://bsky.brid.gy/convert/ap/at://did:bob/app.bsky.feed.post/456',
+                'name': 'RE: https://bsky.app/profile/did:bob/post/456',
+            }],
+        }, ActivityPub.convert(obj), ignore=['contentMap', 'content_is_html', 'to'])
+
     def test_postprocess_as2_idempotent(self):
         for obj in (ACTOR, REPLY_OBJECT, REPLY_OBJECT_WRAPPED, REPLY,
                     NOTE_OBJECT, NOTE, MENTION_OBJECT, MENTION, LIKE,
diff --git a/tests/test_protocol.py b/tests/test_protocol.py
index 319c4ecb..ab4fca7b 100644
--- a/tests/test_protocol.py
+++ b/tests/test_protocol.py
@@ -536,7 +536,8 @@ def test_translate_ids_attachments_mention_tags(self):
             'objectType': 'note',
             'attachments': [
                 {'id': 'other:o:fa:fake:123'},
-                {'url': 'other:o:fa:fake:456'},
+                {'id': 'other:o:fa:fake:456',
+                 'url': 'fake:456'},
             ],
             'tags': [
                 {'objectType': 'mention', 'url': 'other:u:fake:alice'},
@@ -570,7 +571,8 @@ def test_translate_ids_copies(self):
             },
             'attachments': [{
                 'objectType': 'note',
-                'url': 'other:post',
+                'id': 'other:post',
+                'url': 'fake:post',
             }],
         }, OtherFake.translate_ids({
             'objectType': 'activity',