diff --git a/benchs/fib_rec.ml b/benchs/fib_rec.ml
index 4ff984f4..1a3d3288 100644
--- a/benchs/fib_rec.ml
+++ b/benchs/fib_rec.ml
@@ -31,7 +31,8 @@ let run ~psize ~n ~seq ~niter () : unit =
       )
     in
     Printf.printf "fib %d = %d\n%!" n res
-  done
+  done;
+  if not seq then Pool.shutdown (Lazy.force pool)
 
 let () =
   let n = ref 40 in
diff --git a/test/t_resource.ml b/test/t_resource.ml
index 5845c520..a9686867 100644
--- a/test/t_resource.ml
+++ b/test/t_resource.ml
@@ -4,8 +4,10 @@ let ( let@ ) = ( @@ )
 
 (* test proper resource handling *)
 let () =
+  let@ () = Trace_tef.with_setup () in
   let a = Atomic.make 0 in
   for _i = 1 to 1_000 do
+    let@ _sp = Trace.with_span ~__FILE__ ~__LINE__ "loop.step" in
     (* give a chance to domains to die *)
     if _i mod 100 = 0 then Thread.delay 0.8;