diff --git a/activitypub.py b/activitypub.py
index 4bdefbf..16c7a10 100644
--- a/activitypub.py
+++ b/activitypub.py
@@ -46,6 +46,8 @@ CONNEG_HEADERS_AS2_HTML = {
 
 HTTP_SIG_HEADERS = ('Date', 'Host', 'Digest', '(request-target)')
 
+SECURITY_CONTEXT = 'https://w3id.org/security/v1'
+
 # https://seb.jambor.dev/posts/understanding-activitypub-part-4-threads/#the-instance-actor
 _INSTANCE_ACTOR = None
 
@@ -331,7 +333,11 @@ class ActivityPub(User, Protocol):
         if not obj or not obj.as1:
             return {}
         if obj.as2:
-            return obj.as2
+            return {
+                # add back @context since we strip it when we store Objects
+                '@context': [as2.CONTEXT, SECURITY_CONTEXT],
+                **obj.as2,
+            }
 
         translated = cls.translate_ids(obj.as1)
 
@@ -760,8 +766,7 @@ def postprocess_as2_actor(actor, user):
                 'owner': id,
                 'publicKeyPem': user.public_pem().decode(),
             },
-            '@context': (util.get_list(actor, '@context') +
-                         ['https://w3id.org/security/v1']),
+            '@context': (util.get_list(actor, '@context') + [SECURITY_CONTEXT]),
         })
 
     if (user.key.id() not in DOMAINS
diff --git a/tests/test_activitypub.py b/tests/test_activitypub.py
index d90f08c..9da6d10 100644
--- a/tests/test_activitypub.py
+++ b/tests/test_activitypub.py
@@ -1534,7 +1534,7 @@ class ActivityPubTest(TestCase):
 
         resp = self.client.get('/user.com/followers')
         self.assertEqual(200, resp.status_code)
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': 'http://localhost/user.com/followers',
             'type': 'Collection',
@@ -1557,7 +1557,7 @@ class ActivityPubTest(TestCase):
 
         resp = self.client.get(f'/user.com/followers?before={before}')
         self.assertEqual(200, resp.status_code)
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': f'http://localhost/user.com/followers?before={before}',
             'type': 'CollectionPage',
@@ -1610,7 +1610,7 @@ class ActivityPubTest(TestCase):
 
         resp = self.client.get('/user.com/following')
         self.assertEqual(200, resp.status_code)
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': 'http://localhost/user.com/following',
             'summary': "user.com's following",
@@ -1633,7 +1633,7 @@ class ActivityPubTest(TestCase):
 
         resp = self.client.get(f'/user.com/following?after={after}')
         self.assertEqual(200, resp.status_code)
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': f'http://localhost/user.com/following?after={after}',
             'type': 'CollectionPage',
@@ -1687,7 +1687,7 @@ class ActivityPubTest(TestCase):
         self.assertEqual(200, resp.status_code)
 
         after = Object.get_by_id(LIKE['id']).updated.isoformat()
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': 'https://fa.brid.gy/ap/fake:foo/outbox',
             'summary': "fake:foo's outbox",
@@ -1712,7 +1712,7 @@ class ActivityPubTest(TestCase):
         self.assertEqual(200, resp.status_code)
 
         prev = Object.get_by_id(MENTION['id']).updated.isoformat()
-        self.assertEqual({
+        self.assert_equals({
             '@context': 'https://www.w3.org/ns/activitystreams',
             'id': f'https://fa.brid.gy/ap/fake:foo/outbox?after={after}',
             'type': 'CollectionPage',
@@ -2112,7 +2112,7 @@ class ActivityPubUtilsTest(TestCase):
         self.assertEqual({}, ActivityPub.convert(obj))
 
         obj.as2 = {'baz': 'biff'}
-        self.assertEqual({'baz': 'biff'}, ActivityPub.convert(obj))
+        self.assert_equals({'baz': 'biff'}, ActivityPub.convert(obj))
 
         # prevent HTTP fetch to infer protocol
         self.store_object(id='https://mas.to/thing', source_protocol='activitypub')
@@ -2177,6 +2177,18 @@ class ActivityPubUtilsTest(TestCase):
             'object': {'attributedTo': 'biff'},
         }, ActivityPub.convert(obj), ignore=['to'])
 
+    def test_convert_adds_context_to_as2(self):
+        obj = Object(as2={
+            'type': 'Update',
+            'object': ACTOR,
+        })
+        # use assertEquals so that we don't ignore @context
+        self.assertEqual({
+            '@context': [as2.CONTEXT, activitypub.SECURITY_CONTEXT],
+            'type': 'Update',
+            'object': ACTOR,
+        }, ActivityPub.convert(obj))
+
     def test_postprocess_as2_idempotent(self):
         for obj in (ACTOR, REPLY_OBJECT, REPLY_OBJECT_WRAPPED, REPLY,
                     NOTE_OBJECT, NOTE, MENTION_OBJECT, MENTION, LIKE,