diff --git a/src/core/ws_pool.ml b/src/core/ws_pool.ml
index 70d803c8..e10529d9 100644
--- a/src/core/ws_pool.ml
+++ b/src/core/ws_pool.ml
@@ -6,18 +6,7 @@ include Runner
 
 let ( let@ ) = ( @@ )
 
-module Id = struct
-  type t = unit ref
-  (** Unique identifier for a pool *)
-
-  let create () : t = Sys.opaque_identity (ref ())
-  let equal : t -> t -> bool = ( == )
-end
-
 type state = {
-  id_: Id.t;
-      (** Unique to this pool. Used to make sure tasks stay within the same
-          pool. *)
   active: bool A.t;  (** Becomes [false] when the pool is shutdown. *)
   mutable workers: worker_state array;  (** Fixed set of workers. *)
   main_q: WL.task_full Queue.t;
@@ -99,12 +88,15 @@ let schedule_in_main_queue (self : state) task : unit =
        longer permitted *)
     raise Shutdown
 
-let schedule_from_w (self : worker_state) (task : WL.task_full) : unit =
+let schedule_from_anywhere_ (st : state) (task : WL.task_full) : unit =
   match get_current_worker_ () with
-  | Some w when Id.equal self.st.id_ w.st.id_ ->
+  | Some w when st == w.st ->
     (* use worker from the same pool *)
     schedule_on_current_worker w task
-  | _ -> schedule_in_main_queue self.st task
+  | _ -> schedule_in_main_queue st task
+
+let schedule_from_w (w : worker_state) task : unit =
+  schedule_from_anywhere_ w.st task
 
 exception Got_task of WL.task_full
 
@@ -224,9 +216,7 @@ let as_runner_ (self : state) : t =
     ~shutdown:(fun ~wait () -> shutdown_ self ~wait)
     ~run_async:(fun ~fiber f ->
       let task = WL.T_start { fiber; f } in
-      match get_current_worker_ () with
-      | Some wst when wst.st == self -> schedule_from_w wst task
-      | _ -> schedule_in_main_queue self task)
+      schedule_from_anywhere_ self task)
     ~size:(fun () -> size_ self)
     ~num_tasks:(fun () -> num_tasks_ self)
     ()
@@ -243,7 +233,6 @@ type ('a, 'b) create_args =
 let create ?(on_init_thread = default_thread_init_exit_)
     ?(on_exit_thread = default_thread_init_exit_) ?(on_exn = fun _ _ -> ())
     ?num_threads ?name () : t =
-  let pool_id_ = Id.create () in
   let num_domains = Domain_pool_.max_number_of_domains () in
   let num_threads = Util_pool_.num_threads ?num_threads () in
 
@@ -252,7 +241,6 @@ let create ?(on_init_thread = default_thread_init_exit_)
 
   let pool =
     {
-      id_ = pool_id_;
       active = A.make true;
       workers = [||];
       main_q = Queue.create ();