diff --git a/src/Web/ActivityPub.hs b/src/Web/ActivityPub.hs
index bc43e8f..761b637 100644
--- a/src/Web/ActivityPub.hs
+++ b/src/Web/ActivityPub.hs
@@ -171,9 +171,6 @@ secContext = "https://w3id.org/security/v2"
 forgeContext :: Text
 forgeContext = "https://forgefed.org/ns"
 
-extContext :: Text
-extContext = "https://angeley.es/as2-ext"
-
 publicURI :: Text
 publicURI = "https://www.w3.org/ns/activitystreams#Public"
 
@@ -237,7 +234,7 @@ data PublicKey u = PublicKey
     }
 
 instance ActivityPub PublicKey where
-    jsonldContext _ = [secContext, extContext]
+    jsonldContext _ = [secContext]
     parseObject o = do
         mtyp <- optional $ o .: "@type" <|> o .: "type"
         for_ mtyp $ \ t ->
@@ -334,7 +331,7 @@ data SshPublicKey u = SshPublicKey
     }
 
 instance ActivityPub SshPublicKey where
-    jsonldContext _ = [secContext, forgeContext, extContext]
+    jsonldContext _ = [secContext, forgeContext]
     parseObject o = do
         mtyp <- optional $ o .: "@type" <|> o .: "type"
         for_ mtyp $ \ t ->
@@ -438,7 +435,7 @@ data Actor u = Actor
     }
 
 instance ActivityPub Actor where
-    jsonldContext _ = [as2Context, secContext, forgeContext, extContext]
+    jsonldContext _ = [as2Context, secContext, forgeContext]
     parseObject o = do
         mlocal <- parseActorLocal o
         (h, local) <-
@@ -476,8 +473,8 @@ data TicketTracker u = TicketTracker
     , ticketTrackerTeam  :: LocalURI
     }
 
-instance ActivityPub Project where
-    jsonldContext _ = [as2Context, secContext, forgeContext, extContext]
+instance ActivityPub TicketTracker where
+    jsonldContext _ = [as2Context, secContext, forgeContext]
     parseObject o = do
         (h, a) <- parseObject o
         unless (actorType (actorDetail a) == ActorTypeTicketTracker) $
@@ -516,7 +513,7 @@ data Collection a u = Collection
     }
 
 instance (FromJSON a, ToJSON a) => ActivityPub (Collection a) where
-    jsonldContext _ = [as2Context, forgeContext, extContext]
+    jsonldContext _ = [as2Context, forgeContext]
     parseObject o = do
         ObjURI authority id_ <- o .: "id"
         fmap (authority,) $
@@ -574,7 +571,7 @@ data CollectionPage a u = CollectionPage
     }
 
 instance (FromJSON a, ToJSON a) => ActivityPub (CollectionPage a) where
-    jsonldContext _ = [as2Context, forgeContext, extContext]
+    jsonldContext _ = [as2Context, forgeContext]
     parseObject o = do
         PageURI authority id_ <- o .: "id"
         fmap (authority,) $
@@ -610,7 +607,7 @@ instance (FromJSON a, ToJSON a) => ActivityPub (CollectionPage a) where
 data Recipient u = RecipientActor (Actor u) | RecipientCollection (Collection (ObjURI u) u)
 
 instance ActivityPub Recipient where
-    jsonldContext _ = [as2Context, secContext, forgeContext, extContext]
+    jsonldContext _ = [as2Context, secContext, forgeContext]
     parseObject o =
         second RecipientActor <$> parseObject o <|>
         second RecipientCollection <$> parseObject o
@@ -736,7 +733,7 @@ withAuthorityMaybeP a m = do
             else fail "URI authority mismatch"
 
 instance ActivityPub Note where
-    jsonldContext _ = [as2Context, extContext]
+    jsonldContext _ = [as2Context]
     parseObject o = do
         typ <- o .: "type"
         unless (typ == ("Note" :: Text)) $
@@ -1130,7 +1127,7 @@ data Ticket u = Ticket
     }
 
 instance ActivityPub Ticket where
-    jsonldContext _ = [as2Context, forgeContext, extContext]
+    jsonldContext _ = [as2Context, forgeContext]
     parseObject o = do
         typ <- o .: "type"
         unless (typ == ("Ticket" :: Text)) $
@@ -1260,7 +1257,7 @@ data Commit u = Commit
     }
 
 instance ActivityPub Commit where
-    jsonldContext _ = [as2Context, forgeContext, extContext]
+    jsonldContext _ = [as2Context, forgeContext]
     parseObject o = do
         typ <- o .: "type"
         unless (typ == ("Commit" :: Text)) $
@@ -1587,7 +1584,7 @@ data Activity u = Activity
     }
 
 instance ActivityPub Activity where
-    jsonldContext _ = [as2Context, forgeContext, extContext]
+    jsonldContext _ = [as2Context, forgeContext]
     parseObject o = do
         ObjURI a actor <- o .: "actor"
         fmap (a,) $