diff --git a/src/lib_shell/worker.ml b/src/lib_shell/worker.ml
index 3ed893db5..ff661f321 100644
--- a/src/lib_shell/worker.ml
+++ b/src/lib_shell/worker.ml
@@ -184,7 +184,8 @@ module Make
           Lwt_pipe.pop message_queue >>= fun m ->
           return (Some m)
       | Some timeout ->
-          Lwt_pipe.pop_with_timeout timeout message_queue >>= fun m ->
+          Lwt_pipe.pop_with_timeout
+            (Lwt_unix.sleep timeout) message_queue >>= fun m ->
           return m in
     match w.buffer with
     | Queue_buffer message_queue -> pop_queue message_queue
diff --git a/src/lib_stdlib_lwt/lwt_pipe.ml b/src/lib_stdlib_lwt/lwt_pipe.ml
index dec1b1c07..cccc91844 100644
--- a/src/lib_stdlib_lwt/lwt_pipe.ml
+++ b/src/lib_stdlib_lwt/lwt_pipe.ml
@@ -144,9 +144,6 @@ let rec pop_with_timeout timeout q =
   else
     Lwt.return_none
 
-let pop_with_timeout timeout q =
-  pop_with_timeout (Lwt_unix.sleep timeout) q
-
 let rec peek ({ closed ; queue ; _ } as q) =
   if not (Queue.is_empty queue) then
     let (_elt_size, elt) = Queue.peek queue in
diff --git a/src/lib_stdlib_lwt/lwt_pipe.mli b/src/lib_stdlib_lwt/lwt_pipe.mli
index 4a627d703..6b6851053 100644
--- a/src/lib_stdlib_lwt/lwt_pipe.mli
+++ b/src/lib_stdlib_lwt/lwt_pipe.mli
@@ -29,7 +29,7 @@ val pop : 'a t -> 'a Lwt.t
 (** [pop q] is a thread that blocks while [q] is empty, then
     removes and returns the first element in [q]. *)
 
-val pop_with_timeout : float -> 'a t -> 'a option Lwt.t
+val pop_with_timeout : unit Lwt.t -> 'a t -> 'a option Lwt.t
 (** [pop t q] is a thread that blocks while [q] is empty, then
     removes and returns the first element [v] in [q] and
     to return [Some v], unless no message could be popped