diff --git a/src/pool.ml b/src/pool.ml
index ce10656f..7fb77ffc 100644
--- a/src/pool.ml
+++ b/src/pool.ml
@@ -69,6 +69,8 @@ let num_tasks_ (self : state) : int =
   Array.iter (fun q -> n := !n + Bb_queue.size q) self.qs;
   !n
 
+[@@@ifge 5.0]
+
 (* DLA interop *)
 let prepare_for_await () : Dla_.t =
   (* current state *)
@@ -89,6 +91,12 @@ let prepare_for_await () : Dla_.t =
   let t = { Dla_.release; await } in
   t
 
+[@@@else_]
+
+let prepare_for_await () = { Dla_.release = ignore; await = ignore }
+
+[@@@endif]
+
 exception Got_task of task
 
 type around_task = AT_pair : (t -> 'a) * (t -> 'a -> unit) -> around_task
diff --git a/src/suspend_.ml b/src/suspend_.ml
index 172560fc..1a0b55df 100644
--- a/src/suspend_.ml
+++ b/src/suspend_.ml
@@ -33,4 +33,8 @@ let with_suspend ~(run : with_handler:bool -> task -> unit) (f : unit -> unit) :
   E.try_with f () { E.effc }
 
 [@@@ocaml.alert "+unstable"]
+[@@@else_]
+
+let with_suspend ~run:_ f = f ()
+
 [@@@endif]
diff --git a/src/suspend_.mli b/src/suspend_.mli
index bc205616..032bc3e0 100644
--- a/src/suspend_.mli
+++ b/src/suspend_.mli
@@ -48,11 +48,13 @@ val suspend : suspension_handler -> unit
     and a task runner function.
 *)
 
+[@@@endif]
+
 val with_suspend :
   run:(with_handler:bool -> task -> unit) -> (unit -> unit) -> unit
 (** [with_suspend ~run f] runs [f()] in an environment where [suspend]
     will work. If [f()] suspends with suspension handler [h],
     this calls [h ~run k] where [k] is the suspension.
-*)
 
-[@@@endif]
+    This will not do anything on OCaml 4.x.
+*)