diff --git a/apub-core/src/activitystreams.rs b/apub-core/src/activitystreams.rs
index b4f5933..fd8b5f8 100644
--- a/apub-core/src/activitystreams.rs
+++ b/apub-core/src/activitystreams.rs
@@ -96,6 +96,8 @@ pub trait Actor: Object {
 
 pub mod extensions {
     //! Extensions to the ActivityPub traits
+    use std::{rc::Rc, sync::Arc};
+
     use crate::{
         repo::{Dereference, Repo},
         session::Session,
@@ -150,6 +152,86 @@ pub mod extensions {
 
         repo.fetch(D::from(id.clone()), session).await
     }
+
+    impl<'a, T> ActivityExt for &'a T
+    where
+        T: ActivityExt,
+    {
+        type ActorId = T::ActorId;
+        type ObjectId = T::ObjectId;
+
+        fn actor(&self) -> Option<<Self::ActorId as Dereference>::Output> {
+            T::actor(self)
+        }
+
+        fn object(&self) -> Option<<Self::ObjectId as Dereference>::Output> {
+            T::object(self)
+        }
+    }
+
+    impl<'a, T> ActivityExt for &'a mut T
+    where
+        T: ActivityExt,
+    {
+        type ActorId = T::ActorId;
+        type ObjectId = T::ObjectId;
+
+        fn actor(&self) -> Option<<Self::ActorId as Dereference>::Output> {
+            T::actor(self)
+        }
+
+        fn object(&self) -> Option<<Self::ObjectId as Dereference>::Output> {
+            T::object(self)
+        }
+    }
+
+    impl<T> ActivityExt for Box<T>
+    where
+        T: ActivityExt,
+    {
+        type ActorId = T::ActorId;
+        type ObjectId = T::ObjectId;
+
+        fn actor(&self) -> Option<<Self::ActorId as Dereference>::Output> {
+            T::actor(self)
+        }
+
+        fn object(&self) -> Option<<Self::ObjectId as Dereference>::Output> {
+            T::object(self)
+        }
+    }
+
+    impl<T> ActivityExt for Rc<T>
+    where
+        T: ActivityExt,
+    {
+        type ActorId = T::ActorId;
+        type ObjectId = T::ObjectId;
+
+        fn actor(&self) -> Option<<Self::ActorId as Dereference>::Output> {
+            T::actor(self)
+        }
+
+        fn object(&self) -> Option<<Self::ObjectId as Dereference>::Output> {
+            T::object(self)
+        }
+    }
+
+    impl<T> ActivityExt for Arc<T>
+    where
+        T: ActivityExt,
+    {
+        type ActorId = T::ActorId;
+        type ObjectId = T::ObjectId;
+
+        fn actor(&self) -> Option<<Self::ActorId as Dereference>::Output> {
+            T::actor(self)
+        }
+
+        fn object(&self) -> Option<<Self::ObjectId as Dereference>::Output> {
+            T::object(self)
+        }
+    }
 }
 
 impl<'a, T> PublicKey for &'a T