diff --git a/src/lwt/moonpool_lwt.ml b/src/lwt/moonpool_lwt.ml
index 1e1086c0..cbb40758 100644
--- a/src/lwt/moonpool_lwt.ml
+++ b/src/lwt/moonpool_lwt.ml
@@ -21,6 +21,7 @@ module Scheduler_state = struct
     mutex: Mutex.t;
     mutable thread: int;
     closed: bool Atomic.t;
+    cleanup_done: bool Atomic.t;
     mutable as_runner: Moonpool.Runner.t;
     mutable enter_hook: Lwt_main.Enter_iter_hooks.hook option;
     mutable leave_hook: Lwt_main.Leave_iter_hooks.hook option;
@@ -39,6 +40,7 @@ module Scheduler_state = struct
       mutex = Mutex.create ();
       thread = Thread.id (Thread.self ());
       closed = Atomic.make false;
+      cleanup_done = Atomic.make false;
       as_runner = Moonpool.Runner.dummy;
       enter_hook = None;
       leave_hook = None;
@@ -46,12 +48,15 @@ module Scheduler_state = struct
       has_notified = Atomic.make false;
     }
 
+  let[@inline] notify_ (self : st) : unit =
+    if not (Atomic.exchange self.has_notified true) then
+      Lwt_unix.send_notification self.notification
+
   let[@inline never] add_action_from_another_thread_ (self : st) f : unit =
     Mutex.lock self.mutex;
     Queue.push f self.actions_from_other_threads;
     Mutex.unlock self.mutex;
-    if not (Atomic.exchange self.has_notified true) then
-      Lwt_unix.send_notification self.notification
+    notify_ self
 
   let[@inline] on_lwt_thread_ (self : st) : bool =
     Thread.id (Thread.self ()) = self.thread
@@ -71,9 +76,12 @@ module Scheduler_state = struct
            one!)";
       if not (on_lwt_thread_ st) then
         failwith "moonpool-lwt: cleanup from the wrong thread";
-      Option.iter Lwt_main.Enter_iter_hooks.remove st.enter_hook;
-      Option.iter Lwt_main.Leave_iter_hooks.remove st.leave_hook;
-      Lwt_unix.stop_notification st.notification;
+      Atomic.set st.closed true;
+      if not (Atomic.exchange st.cleanup_done true) then (
+        Option.iter Lwt_main.Enter_iter_hooks.remove st.enter_hook;
+        Option.iter Lwt_main.Leave_iter_hooks.remove st.leave_hook;
+        Lwt_unix.stop_notification st.notification
+      );
 
       Atomic.set cur_st None
     | None -> failwith "moonpool-lwt: cleanup failed (no current active state)"
@@ -304,6 +312,8 @@ let lwt_main (f : _ -> 'a) : 'a =
   let finally () = Scheduler_state.cleanup st in
   Fun.protect ~finally @@ fun () ->
   let fut = spawn_lwt (fun () -> f st.as_runner) in
+  (* make sure the scheduler isn't already sleeping *)
+  Scheduler_state.notify_ st;
   Lwt_main.run fut
 
 let[@inline] lwt_main_runner () =