diff --git a/README.md b/README.md
index 40ae042b..ab451e08 100644
--- a/README.md
+++ b/README.md
@@ -24,20 +24,20 @@ In addition, some concurrency and parallelism primitives are provided:
 
 ## Usage
 
-The user can create several thread pools. These pools use regular posix threads,
-but the threads are spread across multiple domains (on OCaml 5), which enables
-parallelism.
+The user can create several thread pools (implementing the interface `Runner.t`).
+These pools use regular posix threads, but the threads are spread across
+multiple domains (on OCaml 5), which enables parallelism.
 
-The function `Pool.run_async pool task` runs `task()` on one of the workers
-of `pool`, as soon as one is available. No result is returned.
+The function `Runner.run_async pool task` schedules `task()` to run on one of
+the workers of `pool`, as soon as one is available. No result is returned by `run_async`.
 
 ```ocaml
 # #require "threads";;
-# let pool = Moonpool.Pool.create ~min:4 ();;
+# let pool = Moonpool.Fifo_pool.create ~min:4 ();;
 val pool : Moonpool.Runner.t = <abstr>
 
 # begin
-   Moonpool.Pool.run_async pool
+   Moonpool.Runner.run_async pool
     (fun () ->
         Thread.delay 0.1;
         print_endline "running from the pool");
@@ -49,11 +49,13 @@ running from the pool
 - : unit = ()
 ```
 
-To wait until the task is done, you can use `Pool.run_wait_block` instead:
+To wait until the task is done, you can use `Runner.run_wait_block`[^1] instead:
+
+[^1]: beware of deadlock! See documentation for more details.
 
 ```ocaml
 # begin
-   Moonpool.Pool.run_wait_block pool
+   Moonpool.Runner.run_wait_block pool
     (fun () ->
         Thread.delay 0.1;
         print_endline "running from the pool");
@@ -155,7 +157,7 @@ val expected_sum : int = 5050
 
 On OCaml 5, again using effect handlers, the module `Fork_join`
 implements the [fork-join model](https://en.wikipedia.org/wiki/Fork%E2%80%93join_model).
-It must run on a pool (using [Pool.run] or inside a future via [Future.spawn]).
+It must run on a pool (using [Runner.run_async] or inside a future via [Fut.spawn]).
 
 ```ocaml
 # let rec select_sort arr i len =
@@ -257,7 +259,7 @@ This works for OCaml >= 4.08.
     the same pool, too — this is useful for threads blocking on IO).
 
     A useful analogy is that each domain is a bit like a CPU core, and `Thread.t` is a logical thread running on a core.
-    Multiple threads have to share a single core and do not run in parallel on it[^1].
+    Multiple threads have to share a single core and do not run in parallel on it[^2].
     We can therefore build pools that spread their worker threads on multiple cores to enable parallelism within each pool.
 
 TODO: actually use https://github.com/haesbaert/ocaml-processor to pin domains to cores,
@@ -273,4 +275,4 @@ MIT license.
 $ opam install moonpool
 ```
 
-[^1]: let's not talk about hyperthreading.
+[^2]: let's not talk about hyperthreading.
diff --git a/benchs/fib_rec.ml b/benchs/fib_rec.ml
index 385bfed4..06341ce1 100644
--- a/benchs/fib_rec.ml
+++ b/benchs/fib_rec.ml
@@ -21,7 +21,7 @@ let () = assert (List.init 10 fib_direct = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
 let create_pool ~psize ~kind () =
   match kind with
   | "fifo" -> Fifo_pool.create ~min:psize ()
-  | "pool" -> Pool.create ~min:psize ()
+  | "pool" -> Ws_pool.create ~min:psize ()
   | _ -> assert false
 
 let run ~psize ~n ~seq ~niter ~kind () : unit =
@@ -38,7 +38,7 @@ let run ~psize ~n ~seq ~niter ~kind () : unit =
     in
     Printf.printf "fib %d = %d\n%!" n res
   done;
-  if not seq then Pool.shutdown (Lazy.force pool)
+  if not seq then Ws_pool.shutdown (Lazy.force pool)
 
 let () =
   let n = ref 40 in
diff --git a/benchs/pi.ml b/benchs/pi.ml
index 01017ae9..65304a80 100644
--- a/benchs/pi.ml
+++ b/benchs/pi.ml
@@ -21,9 +21,9 @@ let with_pool ~kind f =
   match kind with
   | "pool" ->
     if !j = 0 then
-      Pool.with_ ~per_domain:1 f
+      Ws_pool.with_ ~per_domain:1 f
     else
-      Pool.with_ ~min:!j f
+      Ws_pool.with_ ~min:!j f
   | "fifo" ->
     if !j = 0 then
       Fifo_pool.with_ ~per_domain:1 f
@@ -35,7 +35,7 @@ let with_pool ~kind f =
 let run_par1 ~kind (num_steps : int) : float =
   let@ pool = with_pool ~kind () in
 
-  let num_tasks = Pool.size pool in
+  let num_tasks = Ws_pool.size pool in
 
   let step = 1. /. float num_steps in
   let global_sum = Lock.create 0. in
@@ -64,12 +64,12 @@ let run_par1 ~kind (num_steps : int) : float =
 let run_fork_join ~kind num_steps : float =
   let@ pool = with_pool ~kind () in
 
-  let num_tasks = Pool.size pool in
+  let num_tasks = Ws_pool.size pool in
 
   let step = 1. /. float num_steps in
   let global_sum = Lock.create 0. in
 
-  Pool.run_wait_block pool (fun () ->
+  Ws_pool.run_wait_block pool (fun () ->
       Fork_join.for_
         ~chunk_size:(3 + (num_steps / num_tasks))
         num_steps
diff --git a/src/fut.ml b/src/fut.ml
index 42767b61..0a5332ed 100644
--- a/src/fut.ml
+++ b/src/fut.ml
@@ -97,7 +97,7 @@ let spawn ~on f : _ t =
     fulfill promise res
   in
 
-  Pool.run_async on task;
+  Runner.run_async on task;
   fut
 
 let reify_error (f : 'a t) : 'a or_error t =
@@ -131,7 +131,7 @@ let map ?on ~f fut : _ t =
 
         match on with
         | None -> map_and_fulfill ()
-        | Some on -> Pool.run_async on map_and_fulfill);
+        | Some on -> Runner.run_async on map_and_fulfill);
 
     fut2
 
@@ -158,14 +158,14 @@ let bind ?on ~f fut : _ t =
     | None -> apply_f_to_res r
     | Some on ->
       let fut2, promise = make () in
-      Pool.run_async on (bind_and_fulfill r promise);
+      Runner.run_async on (bind_and_fulfill r promise);
       fut2)
   | None ->
     let fut2, promise = make () in
     on_result fut (fun r ->
         match on with
         | None -> bind_and_fulfill r promise ()
-        | Some on -> Pool.run_async on (bind_and_fulfill r promise));
+        | Some on -> Runner.run_async on (bind_and_fulfill r promise));
 
     fut2
 
@@ -403,7 +403,7 @@ module type INFIX = sig
 end
 
 module Infix_ (X : sig
-  val pool : Pool.t option
+  val pool : Runner.t option
 end) : INFIX = struct
   let[@inline] ( >|= ) x f = map ?on:X.pool ~f x
   let[@inline] ( >>= ) x f = bind ?on:X.pool ~f x
@@ -420,7 +420,7 @@ end)
 include Infix_local
 
 module Infix (X : sig
-  val pool : Pool.t
+  val pool : Runner.t
 end) =
 Infix_ (struct
   let pool = Some X.pool
diff --git a/src/moonpool.ml b/src/moonpool.ml
index fb0a3661..ed1af755 100644
--- a/src/moonpool.ml
+++ b/src/moonpool.ml
@@ -9,7 +9,8 @@ module Chan = Chan
 module Fork_join = Fork_join
 module Fut = Fut
 module Lock = Lock
-module Pool = Pool
+module Pool = Fifo_pool
+module Ws_pool = Ws_pool
 module Runner = Runner
 module Fifo_pool = Fifo_pool
 
diff --git a/src/moonpool.mli b/src/moonpool.mli
index 6edeb1e7..4028e858 100644
--- a/src/moonpool.mli
+++ b/src/moonpool.mli
@@ -9,10 +9,14 @@
   primitives such as guarding locks ({!Lock.t}) and futures ({!Fut.t}).
 *)
 
-module Pool = Pool
+module Ws_pool = Ws_pool
 module Fifo_pool = Fifo_pool
 module Runner = Runner
 
+module Pool = Fifo_pool
+[@@deprecated "use Fifo_pool or Ws_pool"]
+(** Default pool. Please explicitly pick an implementation instead. *)
+
 val start_thread_on_some_domain : ('a -> unit) -> 'a -> Thread.t
 (** Similar to {!Thread.create}, but it picks a background domain at random
     to run the thread. This ensures that we don't always pick the same domain
diff --git a/src/pool.ml b/src/ws_pool.ml
similarity index 91%
rename from src/pool.ml
rename to src/ws_pool.ml
index 01a093b3..fcf5eed9 100644
--- a/src/pool.ml
+++ b/src/ws_pool.ml
@@ -4,9 +4,6 @@ include Runner
 
 let ( let@ ) = ( @@ )
 
-type thread_loop_wrapper =
-  thread:Thread.t -> pool:t -> (unit -> unit) -> unit -> unit
-
 type worker_state = {
   mutable thread: Thread.t;
   q: task WSQ.t;  (** Work stealing queue *)
@@ -227,7 +224,6 @@ let shutdown_ ~wait (self : state) : unit =
 type ('a, 'b) create_args =
   ?on_init_thread:(dom_id:int -> t_id:int -> unit -> unit) ->
   ?on_exit_thread:(dom_id:int -> t_id:int -> unit -> unit) ->
-  ?thread_wrappers:thread_loop_wrapper list ->
   ?on_exn:(exn -> Printexc.raw_backtrace -> unit) ->
   ?around_task:(t -> 'b) * (t -> 'b -> unit) ->
   ?min:int ->
@@ -236,9 +232,8 @@ type ('a, 'b) create_args =
 (** Arguments used in {!create}. See {!create} for explanations. *)
 
 let create ?(on_init_thread = default_thread_init_exit_)
-    ?(on_exit_thread = default_thread_init_exit_) ?(thread_wrappers = [])
-    ?(on_exn = fun _ _ -> ()) ?around_task ?min:(min_threads = 1)
-    ?(per_domain = 0) () : t =
+    ?(on_exit_thread = default_thread_init_exit_) ?(on_exn = fun _ _ -> ())
+    ?around_task ?min:(min_threads = 1) ?(per_domain = 0) () : t =
   (* wrapper *)
   let around_task =
     match around_task with
@@ -294,16 +289,9 @@ let create ?(on_init_thread = default_thread_init_exit_)
       on_init_thread ~dom_id:dom_idx ~t_id ();
 
       let run () = worker_thread_ pool runner w ~on_exn ~around_task in
-      (* the actual worker loop is [worker_thread_], with all
-         wrappers for this pool and for all pools (global_thread_wrappers_) *)
-      let run' =
-        List.fold_left
-          (fun run f -> f ~thread ~pool:runner run)
-          run thread_wrappers
-      in
 
       (* now run the main loop *)
-      Fun.protect run' ~finally:(fun () ->
+      Fun.protect run ~finally:(fun () ->
           (* on termination, decrease refcount of underlying domain *)
           D_pool_.decr_on dom_idx);
       on_exit_thread ~dom_id:dom_idx ~t_id ()
@@ -335,11 +323,11 @@ let create ?(on_init_thread = default_thread_init_exit_)
 
   runner
 
-let with_ ?on_init_thread ?on_exit_thread ?thread_wrappers ?on_exn ?around_task
-    ?min ?per_domain () f =
+let with_ ?on_init_thread ?on_exit_thread ?on_exn ?around_task ?min ?per_domain
+    () f =
   let pool =
-    create ?on_init_thread ?on_exit_thread ?thread_wrappers ?on_exn ?around_task
-      ?min ?per_domain ()
+    create ?on_init_thread ?on_exit_thread ?on_exn ?around_task ?min ?per_domain
+      ()
   in
   let@ () = Fun.protect ~finally:(fun () -> shutdown pool) in
   f pool
diff --git a/src/pool.mli b/src/ws_pool.mli
similarity index 76%
rename from src/pool.mli
rename to src/ws_pool.mli
index f7a42633..4775024c 100644
--- a/src/pool.mli
+++ b/src/ws_pool.mli
@@ -1,7 +1,13 @@
-(** Thread pool.
+(** Work-stealing thread pool.
 
-    A pool of threads. The pool contains a fixed number of threads that
-    wait for work items to come, process these, and loop.
+    A pool of threads with a worker-stealing scheduler.
+    The pool contains a fixed number of threads that wait for work
+    items to come, process these, and loop.
+
+    This is good for CPU-intensive tasks that feature a lot of small tasks.
+    Note that tasks will not always be processed in the order they are
+    scheduled, so this is not great for workloads where the latency
+    of individual tasks matter (for that see {!Fifo_pool}).
 
     This implements {!Runner.t} since 0.3.
 
@@ -15,18 +21,9 @@
 
 include module type of Runner
 
-type thread_loop_wrapper =
-  thread:Thread.t -> pool:t -> (unit -> unit) -> unit -> unit
-(** A thread wrapper [f] takes the current thread, the current pool,
-      and the worker function [loop : unit -> unit] which is
-      the worker's main loop, and returns a new loop function.
-      By default it just returns the same loop function but it can be used
-      to install tracing, effect handlers, etc. *)
-
 type ('a, 'b) create_args =
   ?on_init_thread:(dom_id:int -> t_id:int -> unit -> unit) ->
   ?on_exit_thread:(dom_id:int -> t_id:int -> unit -> unit) ->
-  ?thread_wrappers:thread_loop_wrapper list ->
   ?on_exn:(exn -> Printexc.raw_backtrace -> unit) ->
   ?around_task:(t -> 'b) * (t -> 'b -> unit) ->
   ?min:int ->
@@ -47,8 +44,6 @@ val create : (unit -> t, _) create_args
        If both [min] and [per_domain] are specified, the maximum of both
        [min] and [per_domain * num_of_domains] is used.
      @param on_exit_thread called at the end of each thread in the pool
-     @param thread_wrappers a list of {!thread_loop_wrapper} functions
-     to use for this pool's workers.
      @param around_task a pair of [before, after], where [before pool] is called
       before a task is processed,
       on the worker thread about to run it, and returns [x]; and [after pool x] is called by
diff --git a/test/effect-based/t_fib1.ml b/test/effect-based/t_fib1.ml
index e8d2f534..ca3f2861 100644
--- a/test/effect-based/t_fib1.ml
+++ b/test/effect-based/t_fib1.ml
@@ -26,13 +26,13 @@ let fib ~on x : int Fut.t =
 let () = assert (List.init 10 fib_direct = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
 
 let fib_40 : int =
-  let pool = Pool.create ~min:8 () in
+  let pool = Ws_pool.create ~min:8 () in
   fib ~on:pool 40 |> Fut.wait_block_exn
 
 let () = Printf.printf "fib 40 = %d\n%!" fib_40
 
 let run_test () =
-  let pool = Pool.create ~min:8 () in
+  let pool = Ws_pool.create ~min:8 () in
 
   assert (
     List.init 10 (fib ~on:pool)
@@ -42,7 +42,7 @@ let run_test () =
   let fibs = Array.init 3 (fun _ -> fib ~on:pool 40) in
 
   let res = Fut.join_array fibs |> Fut.wait_block in
-  Pool.shutdown pool;
+  Ws_pool.shutdown pool;
 
   assert (res = Ok (Array.make 3 fib_40))
 
diff --git a/test/effect-based/t_fib_fork_join.ml b/test/effect-based/t_fib_fork_join.ml
index c6898833..bdf60337 100644
--- a/test/effect-based/t_fib_fork_join.ml
+++ b/test/effect-based/t_fib_fork_join.ml
@@ -27,13 +27,13 @@ let fib ~on x : int Fut.t =
 let () = assert (List.init 10 fib_direct = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
 
 let fib_40 : int =
-  let pool = Pool.create ~min:8 () in
+  let pool = Ws_pool.create ~min:8 () in
   fib ~on:pool 40 |> Fut.wait_block_exn
 
 let () = Printf.printf "fib 40 = %d\n%!" fib_40
 
 let run_test () =
-  let pool = Pool.create ~min:8 () in
+  let pool = Ws_pool.create ~min:8 () in
 
   assert (
     List.init 10 (fib ~on:pool)
@@ -43,7 +43,7 @@ let run_test () =
   let fibs = Array.init 3 (fun _ -> fib ~on:pool 40) in
 
   let res = Fut.join_array fibs |> Fut.wait_block in
-  Pool.shutdown pool;
+  Ws_pool.shutdown pool;
 
   assert (res = Ok (Array.make 3 fib_40))
 
diff --git a/test/effect-based/t_fib_fork_join_all.ml b/test/effect-based/t_fib_fork_join_all.ml
index e1ae83f4..ed82902e 100644
--- a/test/effect-based/t_fib_fork_join_all.ml
+++ b/test/effect-based/t_fib_fork_join_all.ml
@@ -22,13 +22,13 @@ let rec fib x : int =
   )
 
 let fib_40 : int =
-  let@ pool = Pool.with_ ~min:8 () in
+  let@ pool = Ws_pool.with_ ~min:8 () in
   Fut.spawn ~on:pool (fun () -> fib 40) |> Fut.wait_block_exn
 
 let () = Printf.printf "fib 40 = %d\n%!" fib_40
 
 let run_test () =
-  let@ pool = Pool.with_ ~min:8 () in
+  let@ pool = Ws_pool.with_ ~min:8 () in
 
   let fut =
     Fut.spawn ~on:pool (fun () ->
@@ -37,7 +37,7 @@ let run_test () =
   in
 
   let res = Fut.wait_block_exn fut in
-  Pool.shutdown pool;
+  Ws_pool.shutdown pool;
 
   assert (res = (Array.make 3 fib_40 |> Array.to_list))
 
diff --git a/test/effect-based/t_fork_join.ml b/test/effect-based/t_fork_join.ml
index 7fc8fa31..5b467187 100644
--- a/test/effect-based/t_fork_join.ml
+++ b/test/effect-based/t_fork_join.ml
@@ -5,11 +5,11 @@ let ( let@ ) = ( @@ )
 
 open! Moonpool
 
-let pool = Pool.create ~min:4 ()
+let pool = Ws_pool.create ~min:4 ()
 
 let () =
   let x =
-    Pool.run_wait_block pool (fun () ->
+    Ws_pool.run_wait_block pool (fun () ->
         let x, y =
           Fork_join.both
             (fun () ->
@@ -25,7 +25,7 @@ let () =
 
 let () =
   try
-    Pool.run_wait_block pool (fun () ->
+    Ws_pool.run_wait_block pool (fun () ->
         Fork_join.both_ignore
           (fun () -> Thread.delay 0.005)
           (fun () ->
@@ -36,21 +36,21 @@ let () =
 
 let () =
   let par_sum =
-    Pool.run_wait_block pool (fun () ->
+    Ws_pool.run_wait_block pool (fun () ->
         Fork_join.all_init 42 (fun i -> i * i) |> List.fold_left ( + ) 0)
   in
   let exp_sum = List.init 42 (fun x -> x * x) |> List.fold_left ( + ) 0 in
   assert (par_sum = exp_sum)
 
 let () =
-  Pool.run_wait_block pool (fun () ->
+  Ws_pool.run_wait_block pool (fun () ->
       Fork_join.for_ 0 (fun _ _ -> assert false));
   ()
 
 let () =
   let total_sum = Atomic.make 0 in
 
-  Pool.run_wait_block pool (fun () ->
+  Ws_pool.run_wait_block pool (fun () ->
       Fork_join.for_ ~chunk_size:5 100 (fun low high ->
           (* iterate on the range sequentially. The range should have 5 items or less. *)
           let local_sum = ref 0 in
@@ -63,7 +63,7 @@ let () =
 let () =
   let total_sum = Atomic.make 0 in
 
-  Pool.run_wait_block pool (fun () ->
+  Ws_pool.run_wait_block pool (fun () ->
       Fork_join.for_ ~chunk_size:1 100 (fun low high ->
           assert (low = high);
           ignore (Atomic.fetch_and_add total_sum low : int)));
@@ -270,7 +270,7 @@ end
 let t_eval =
   let arb = Q.set_stats [ "size", Evaluator.size ] Evaluator.arb in
   Q.Test.make ~name:"same eval" arb (fun e ->
-      let@ pool = Pool.with_ ~min:4 () in
+      let@ pool = Ws_pool.with_ ~min:4 () in
       (* Printf.eprintf "eval %s\n%!" (Evaluator.show e); *)
       let x = Evaluator.eval_seq e in
       let y = Evaluator.eval_fork_join ~pool e in
@@ -288,8 +288,8 @@ let t_for_nested ~min ~chunk_size () =
       let ref_l2 = List.map (List.map neg) ref_l1 in
 
       let l1, l2 =
-        let@ pool = Pool.with_ ~min () in
-        let@ () = Pool.run_wait_block pool in
+        let@ pool = Ws_pool.with_ ~min () in
+        let@ () = Ws_pool.run_wait_block pool in
         let l1 =
           Fork_join.map_list ~chunk_size (Fork_join.map_list ~chunk_size neg) l
         in
@@ -310,8 +310,8 @@ let t_map ~chunk_size () =
   Q.Test.make ~name:"map1"
     Q.(small_list small_int |> Q.set_stats [ "len", List.length ])
     (fun l ->
-      let@ pool = Pool.with_ ~min:4 () in
-      let@ () = Pool.run_wait_block pool in
+      let@ pool = Ws_pool.with_ ~min:4 () in
+      let@ () = Ws_pool.run_wait_block pool in
 
       let a1 =
         Fork_join.map_list ~chunk_size string_of_int l |> Array.of_list
diff --git a/test/effect-based/t_fork_join_heavy.ml b/test/effect-based/t_fork_join_heavy.ml
index be86299a..ad9f7044 100644
--- a/test/effect-based/t_fork_join_heavy.ml
+++ b/test/effect-based/t_fork_join_heavy.ml
@@ -27,8 +27,8 @@ let run ~min () =
     let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "step" in
 
     let l1, l2 =
-      let@ pool = Pool.with_ ~min () in
-      let@ () = Pool.run_wait_block pool in
+      let@ pool = Ws_pool.with_ ~min () in
+      let@ () = Ws_pool.run_wait_block pool in
 
       let l1, l2 =
         Fork_join.both
diff --git a/test/effect-based/t_futs1.ml b/test/effect-based/t_futs1.ml
index be58f50b..182ca9d5 100644
--- a/test/effect-based/t_futs1.ml
+++ b/test/effect-based/t_futs1.ml
@@ -2,7 +2,7 @@
 
 open! Moonpool
 
-let pool = Pool.create ~min:4 ()
+let pool = Ws_pool.create ~min:4 ()
 
 let () =
   let fut = Array.init 10 (fun i -> Fut.spawn ~on:pool (fun () -> i)) in
diff --git a/test/effect-based/t_many.ml b/test/effect-based/t_many.ml
index 23e1a929..4362932c 100644
--- a/test/effect-based/t_many.ml
+++ b/test/effect-based/t_many.ml
@@ -34,15 +34,15 @@ let () =
    run ~pool ());
 
   (print_endline "with WS(1)";
-   let@ pool = Pool.with_ ~min:1 () in
+   let@ pool = Ws_pool.with_ ~min:1 () in
    run ~pool ());
 
   (print_endline "with WS(2)";
-   let@ pool = Pool.with_ ~min:2 () in
+   let@ pool = Ws_pool.with_ ~min:2 () in
    run ~pool ());
 
   (print_endline "with WS(4)";
-   let@ pool = Pool.with_ ~min:4 () in
+   let@ pool = Ws_pool.with_ ~min:4 () in
    run ~pool ());
 
   ()
diff --git a/test/effect-based/t_sort.ml b/test/effect-based/t_sort.ml
index a732c740..8d3fe17c 100644
--- a/test/effect-based/t_sort.ml
+++ b/test/effect-based/t_sort.ml
@@ -59,7 +59,7 @@ let rec quicksort arr i len : unit =
       (fun () -> quicksort arr !low (len - (!low - i)))
   )
 
-let pool = Moonpool.Pool.create ~min:8 ()
+let pool = Moonpool.Ws_pool.create ~min:8 ()
 
 let () =
   let arr = Array.init 400_000 (fun _ -> Random.int 300_000) in
diff --git a/test/t_bench1.ml b/test/t_bench1.ml
index abf4a7f2..95cd87a5 100644
--- a/test/t_bench1.ml
+++ b/test/t_bench1.ml
@@ -8,7 +8,7 @@ let rec fib x =
 
 let run ~psize ~n ~j () : _ Fut.t =
   Printf.printf "pool size=%d, n=%d, j=%d\n%!" psize n j;
-  let pool = Pool.create ~min:psize ~per_domain:0 () in
+  let pool = Ws_pool.create ~min:psize ~per_domain:0 () in
 
   (* TODO: a ppx for tracy so we can use instrumentation *)
   let loop () =
diff --git a/test/t_chan_train.ml b/test/t_chan_train.ml
index 5d1c40ef..bb3e24f7 100644
--- a/test/t_chan_train.ml
+++ b/test/t_chan_train.ml
@@ -1,7 +1,7 @@
 open Moonpool
 
 (* large pool, some of our tasks below are long lived *)
-let pool = Pool.create ~min:30 ()
+let pool = Ws_pool.create ~min:30 ()
 
 open (val Fut.infix pool)
 
diff --git a/test/t_fib.ml b/test/t_fib.ml
index f54d7118..3a98e395 100644
--- a/test/t_fib.ml
+++ b/test/t_fib.ml
@@ -5,7 +5,7 @@ let ( let@ ) = ( @@ )
 let with_pool ~kind () f =
   match kind with
   | `Fifo_pool -> Fifo_pool.with_ ~min:4 () f
-  | `Pool -> Pool.with_ ~min:4 () f
+  | `Ws_pool -> Ws_pool.with_ ~min:4 () f
 
 let rec fib x =
   if x <= 1 then
@@ -18,7 +18,7 @@ let () = assert (List.init 10 fib = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
 let run_test ~pool () =
   let fibs = Array.init 30 (fun n -> Fut.spawn ~on:pool (fun () -> fib n)) in
   let res = Fut.join_array fibs |> Fut.wait_block in
-  Pool.shutdown pool;
+  Ws_pool.shutdown pool;
 
   assert (
     res
@@ -74,5 +74,5 @@ let run ~kind () =
   Array.iter Thread.join jobs
 
 let () =
-  run ~kind:`Pool ();
+  run ~kind:`Ws_pool ();
   run ~kind:`Fifo_pool ()
diff --git a/test/t_fib_rec.ml b/test/t_fib_rec.ml
index 01cd7c16..de704f34 100644
--- a/test/t_fib_rec.ml
+++ b/test/t_fib_rec.ml
@@ -25,9 +25,9 @@ let () = assert (List.init 10 fib_direct = [ 1; 1; 2; 3; 5; 8; 13; 21; 34; 55 ])
 let fib_40 : int lazy_t =
   lazy
     (let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "fib40" in
-     let pool = Pool.create ~min:8 () in
+     let pool = Ws_pool.create ~min:8 () in
      let r = fib ~on:pool 40 |> Fut.wait_block_exn in
-     Pool.shutdown pool;
+     Ws_pool.shutdown pool;
      r)
 
 let run_test ~pool () =
@@ -49,7 +49,7 @@ let run_test ~pool () =
 
 let run_test_size ~size () =
   Printf.printf "test pool(%d)\n%!" size;
-  let@ pool = Pool.with_ ~min:size () in
+  let@ pool = Ws_pool.with_ ~min:size () in
   run_test ~pool ()
 
 let run_test_fifo ~size () =
diff --git a/test/t_futs1.ml b/test/t_futs1.ml
index 930c8bdc..ee2d96a6 100644
--- a/test/t_futs1.ml
+++ b/test/t_futs1.ml
@@ -1,7 +1,7 @@
 open! Moonpool
 
-let pool = Pool.create ~min:4 ()
-let pool2 = Pool.create ~min:2 ()
+let pool = Ws_pool.create ~min:4 ()
+let pool2 = Ws_pool.create ~min:2 ()
 
 let () =
   let fut = Fut.return 1 in
diff --git a/test/t_props.ml b/test/t_props.ml
index be586251..9fa64fbe 100644
--- a/test/t_props.ml
+++ b/test/t_props.ml
@@ -8,7 +8,7 @@ let add_test t = tests := t :: !tests
 let with_pool ~kind () f =
   match kind with
   | `Fifo_pool -> Fifo_pool.with_ ~min:4 ~per_domain:1 () f
-  | `Pool -> Pool.with_ ~min:4 ~per_domain:1 () f
+  | `Ws_pool -> Ws_pool.with_ ~min:4 ~per_domain:1 () f
 
 let () =
   add_test @@ fun ~kind ->
@@ -48,7 +48,7 @@ let () =
 
 let () =
   let tests =
-    List.map (fun t -> [ t ~kind:`Fifo_pool; t ~kind:`Pool ]) !tests
+    List.map (fun t -> [ t ~kind:`Fifo_pool; t ~kind:`Ws_pool ]) !tests
     |> List.flatten
   in
   QCheck_base_runner.run_tests_main tests
diff --git a/test/t_resource.ml b/test/t_resource.ml
index 005ed4c3..c990f708 100644
--- a/test/t_resource.ml
+++ b/test/t_resource.ml
@@ -5,7 +5,7 @@ let ( let@ ) = ( @@ )
 let with_pool ~kind () f =
   match kind with
   | `Fifo_pool -> Fifo_pool.with_ ~min:4 ~per_domain:1 () f
-  | `Pool -> Pool.with_ ~min:4 ~per_domain:1 () f
+  | `Ws_pool -> Ws_pool.with_ ~min:4 ~per_domain:1 () f
 
 (* test proper resource handling *)
 let run ~kind () =
@@ -18,10 +18,10 @@ let run ~kind () =
 
     (* allocate a new pool at each iteration *)
     let@ p = with_pool ~kind () in
-    Pool.run_wait_block p (fun () -> Atomic.incr a)
+    Ws_pool.run_wait_block p (fun () -> Atomic.incr a)
   done;
   assert (Atomic.get a = 1_000)
 
 let () =
-  run ~kind:`Pool ();
+  run ~kind:`Ws_pool ();
   run ~kind:`Fifo_pool ()
diff --git a/test/t_tree_futs.ml b/test/t_tree_futs.ml
index 83a9d80c..3507be0a 100644
--- a/test/t_tree_futs.ml
+++ b/test/t_tree_futs.ml
@@ -5,7 +5,7 @@ let ( let@ ) = ( @@ )
 let with_pool ~kind ~j () f =
   match kind with
   | `Fifo_pool -> Fifo_pool.with_ ~min:j () f
-  | `Pool -> Pool.with_ ~min:j () f
+  | `Ws_pool -> Ws_pool.with_ ~min:j () f
 
 type 'a tree =
   | Leaf of 'a
@@ -88,5 +88,5 @@ let () =
   (*
   Tracy_client_trace.setup ();
    *)
-  run_main ~kind:`Pool ();
+  run_main ~kind:`Ws_pool ();
   run_main ~kind:`Fifo_pool ()
diff --git a/test/t_unfair.ml b/test/t_unfair.ml
index b6dc5884..f535a450 100644
--- a/test/t_unfair.ml
+++ b/test/t_unfair.ml
@@ -15,32 +15,32 @@ let run ~kind () =
     let on_init_thread ~dom_id:_ ~t_id () =
       Trace.set_thread_name (Printf.sprintf "pool worker %d" t_id)
     and around_task =
-      ( (fun self -> Trace.counter_int "n_tasks" (Pool.num_tasks self)),
-        fun self () -> Trace.counter_int "n_tasks" (Pool.num_tasks self) )
+      ( (fun self -> Trace.counter_int "n_tasks" (Ws_pool.num_tasks self)),
+        fun self () -> Trace.counter_int "n_tasks" (Ws_pool.num_tasks self) )
     in
 
     match kind with
     | `Simple -> Fifo_pool.create ~min:3 ~on_init_thread ~around_task ()
-    | `Pool -> Pool.create ~min:3 ~on_init_thread ~around_task ()
+    | `Ws_pool -> Ws_pool.create ~min:3 ~on_init_thread ~around_task ()
   in
 
   (* make all threads busy *)
-  Pool.run_async pool (sleep_for 0.01);
-  Pool.run_async pool (sleep_for 0.01);
-  Pool.run_async pool (sleep_for 0.05);
+  Ws_pool.run_async pool (sleep_for 0.01);
+  Ws_pool.run_async pool (sleep_for 0.01);
+  Ws_pool.run_async pool (sleep_for 0.05);
 
   let t = Unix.gettimeofday () in
   for _i = 1 to 100 do
     let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "schedule step" in
-    Pool.run_async pool (sleep_for 0.001);
-    Pool.run_async pool (sleep_for 0.001);
-    Pool.run_async pool (sleep_for 0.01)
+    Ws_pool.run_async pool (sleep_for 0.001);
+    Ws_pool.run_async pool (sleep_for 0.001);
+    Ws_pool.run_async pool (sleep_for 0.01)
   done;
 
-  Printf.printf "pool size: %d\n%!" (Pool.num_tasks pool);
+  Printf.printf "pool size: %d\n%!" (Ws_pool.num_tasks pool);
   (let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "shutdown" in
-   Pool.shutdown pool);
-  Printf.printf "pool size after shutdown: %d\n%!" (Pool.num_tasks pool);
+   Ws_pool.shutdown pool);
+  Printf.printf "pool size after shutdown: %d\n%!" (Ws_pool.num_tasks pool);
 
   let elapsed = Unix.gettimeofday () -. t in
   Printf.printf "elapsed: %.4fs\n%!" elapsed
@@ -49,4 +49,4 @@ let () =
   let@ () = Trace_tef.with_setup () in
   let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "main" in
   run ~kind:`Simple ();
-  run ~kind:`Pool ()
+  run ~kind:`Ws_pool ()