diff --git a/worker-sys/src/types/durable_object.rs b/worker-sys/src/types/durable_object.rs
index cb0f53f2..04f8503c 100644
--- a/worker-sys/src/types/durable_object.rs
+++ b/worker-sys/src/types/durable_object.rs
@@ -15,6 +15,7 @@ pub use transaction::*;
 #[wasm_bindgen]
 extern "C" {
     #[wasm_bindgen(extends=js_sys::Object)]
+    #[derive(Clone)]
     pub type DurableObject;
 
     #[wasm_bindgen(method, catch, js_name=fetch)]
diff --git a/worker-sys/src/types/durable_object/namespace.rs b/worker-sys/src/types/durable_object/namespace.rs
index f75453a7..e7ba7600 100644
--- a/worker-sys/src/types/durable_object/namespace.rs
+++ b/worker-sys/src/types/durable_object/namespace.rs
@@ -5,6 +5,7 @@ use crate::types::{DurableObject, DurableObjectId};
 #[wasm_bindgen]
 extern "C" {
     #[wasm_bindgen(extends=js_sys::Object)]
+    #[derive(Clone)]
     pub type DurableObjectNamespace;
 
     #[wasm_bindgen(method, catch, js_name=idFromName)]
diff --git a/worker/src/durable.rs b/worker/src/durable.rs
index fdd19acc..cd2a507d 100644
--- a/worker/src/durable.rs
+++ b/worker/src/durable.rs
@@ -40,6 +40,9 @@ pub struct Stub {
     inner: EdgeDurableObject,
 }
 
+unsafe impl Send for Stub {}
+unsafe impl Sync for Stub {}
+
 impl Stub {
     /// Send an internal Request to the Durable Object to which the stub points.
     pub async fn fetch_with_request(&self, req: Request) -> Result<Response> {
@@ -59,10 +62,14 @@ impl Stub {
 /// Use an ObjectNamespace to get access to Stubs for communication with a Durable Object instance.
 /// A given namespace can support essentially unlimited Durable Objects, with each Object having
 /// access to a transactional, key-value storage API.
+#[derive(Clone)]
 pub struct ObjectNamespace {
     inner: EdgeObjectNamespace,
 }
 
+unsafe impl Send for ObjectNamespace {}
+unsafe impl Sync for ObjectNamespace {}
+
 impl ObjectNamespace {
     /// This method derives a unique object ID from the given name string. It will always return the
     /// same ID when given the same name as input.