diff --git a/test/t_ws_deque.ml b/test/t_ws_deque.ml
new file mode 100644
index 00000000..4a364166
--- /dev/null
+++ b/test/t_ws_deque.ml
@@ -0,0 +1,99 @@
+module A = Moonpool.Atomic
+module D = Moonpool.Private.Ws_deque_
+
+let ( let@ ) = ( @@ )
+
+let t_simple () =
+  let d = D.create () in
+  assert (D.steal d = None);
+  assert (D.pop d = None);
+  D.push d 1;
+  D.push d 2;
+  assert (D.pop d = Some 2);
+  assert (D.steal d = Some 1);
+  assert (D.steal d = None);
+  assert (D.pop d = None);
+  D.push d 3;
+  assert (D.pop d = Some 3);
+  D.push d 4;
+  D.push d 5;
+  D.push d 6;
+  assert (D.steal d = Some 4);
+  assert (D.steal d = Some 5);
+  assert (D.pop d = Some 6);
+  assert (D.pop d = None);
+
+  Printf.printf "basic tests passed\n";
+  ()
+
+(* big heavy test *)
+let t_heavy () =
+  let sum = A.make 0 in
+  let ref_sum = ref 0 in
+
+  let[@inline] add_to_sum x = ignore (A.fetch_and_add sum x : int) in
+
+  let active = A.make true in
+
+  let d = D.create () in
+
+  let stealer_loop () =
+    Trace.set_thread_name "stealer";
+    let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "stealer" in
+    while A.get active do
+      match D.steal d with
+      | None -> Thread.yield ()
+      | Some x -> add_to_sum x
+    done
+  in
+
+  let main_loop () =
+    Trace.set_thread_name "producer";
+    for _i = 1 to 100_000 do
+      let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "main.outer" in
+      for j = 1 to 100 do
+        ref_sum := !ref_sum + j;
+        D.push d j;
+        ref_sum := !ref_sum + j;
+        D.push d j;
+
+        Option.iter (fun x -> add_to_sum x) (D.pop d);
+        Option.iter (fun x -> add_to_sum x) (D.pop d)
+      done;
+
+      (* now compete with stealers to pop *)
+      let continue = ref true in
+      while !continue do
+        match D.pop d with
+        | Some x -> add_to_sum x
+        | None -> continue := false
+      done
+    done
+  in
+
+  let ts =
+    Array.init 6 (fun _ -> Moonpool.start_thread_on_some_domain stealer_loop ())
+  in
+  let t = Moonpool.start_thread_on_some_domain main_loop () in
+
+  (* stop *)
+  A.set active false;
+
+  Trace.message "joining t";
+  Thread.join t;
+  Trace.message "joining stealers";
+  Array.iter Thread.join ts;
+  Trace.message "done";
+
+  let ref_sum = !ref_sum in
+  let sum = A.get sum in
+
+  Printf.printf "ref sum = %d, sum = %d\n%!" ref_sum sum;
+  assert (ref_sum = sum);
+  ()
+
+let () =
+  let@ () = Trace_tef.with_setup () in
+  t_simple ();
+  t_heavy ();
+  ()