diff --git a/test/t_unfair.ml b/test/t_unfair.ml
index 81271046..5d22a663 100644
--- a/test/t_unfair.ml
+++ b/test/t_unfair.ml
@@ -8,18 +8,20 @@ let sleep_for f () =
   let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "sleep" in
   Thread.delay f
 
-let () =
-  let@ () = Trace_tef.with_setup () in
-  let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "main" in
+let run ~kind () =
+  let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "run" in
 
   let pool =
-    Pool.create ~min:3
-      ~on_init_thread:(fun ~dom_id:_ ~t_id () ->
-        Trace.set_thread_name (Printf.sprintf "pool worker %d" t_id))
-      ~around_task:
-        ( (fun self -> Trace.counter_int "n_tasks" (Pool.num_tasks self)),
-          fun self () -> Trace.counter_int "n_tasks" (Pool.num_tasks self) )
-      ()
+    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) )
+    in
+
+    match kind with
+    | `Simple -> Simple_pool.create ~min:3 ~on_init_thread ~around_task ()
+    | `Pool -> Pool.create ~min:3 ~on_init_thread ~around_task ()
   in
 
   (* make all threads busy *)
@@ -42,3 +44,9 @@ let () =
 
   let elapsed = Unix.gettimeofday () -. t in
   Printf.printf "elapsed: %.4fs\n%!" elapsed
+
+let () =
+  let@ () = Trace_tef.with_setup () in
+  let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "main" in
+  run ~kind:`Simple ();
+  run ~kind:`Pool ()