diff --git a/src/io/ev_loop.ml b/src/io/ev_loop.ml
index 7cff644f..fa5616fb 100644
--- a/src/io/ev_loop.ml
+++ b/src/io/ev_loop.ml
@@ -60,8 +60,6 @@ module Per_fd = struct
     mutable writes: IO_wait.t list;
   }
 
-  let[@inline] is_empty self = self.reads = [] && self.writes = []
-
   let update_event (self : t) ~(poll : Poll.t) : unit =
     let ev =
       match self.reads, self.writes with
@@ -71,6 +69,9 @@ module Per_fd = struct
       | [], _ :: _ -> Poll.Event.write
       | _ :: _, _ :: _ -> Poll.Event.read_write
     in
+    Printf.eprintf "poll.set %d {rd=%b, wr=%b}\n%!"
+      (Obj.magic self.fd.fd : int)
+      ev.readable ev.writable;
     Poll.set poll self.fd.fd ev
 end
 
@@ -100,11 +101,11 @@ module IO_tbl = struct
     | Read ->
       self.n_read <- 1 + self.n_read;
       per_fd.reads <- ev :: per_fd.reads;
-      if self.n_read = 0 then Per_fd.update_event per_fd ~poll:self.poll
+      if self.n_read = 1 then Per_fd.update_event per_fd ~poll:self.poll
     | Write ->
       self.n_write <- 1 + self.n_write;
       per_fd.writes <- ev :: per_fd.writes;
-      if self.n_write = 0 then Per_fd.update_event per_fd ~poll:self.poll
+      if self.n_write = 1 then Per_fd.update_event per_fd ~poll:self.poll
 
   let[@inline] trigger_waiter (io : IO_wait.t) =
     if io.active then io.f io.as_cancel_handle
@@ -112,6 +113,7 @@ module IO_tbl = struct
   (** Wake up waiters on FDs who received events *)
   let handle_ready ~ignore_fd (self : t) : unit =
     let update_per_fd (per_fd : Per_fd.t) (event : Poll.Event.t) =
+      Printf.eprintf "handle ready %d\n%!" (Obj.magic per_fd.fd.fd : int);
       if Fd.closed per_fd.fd then
         (* cleanup *)
         Hashtbl.remove self.tbl per_fd.fd.fd
@@ -136,6 +138,8 @@ module IO_tbl = struct
           let per_fd = Hashtbl.find self.tbl fd in
           update_per_fd per_fd event
         ));
+    Poll.clear self.poll;
+
     ()
 
   (** Remove closed FDs *)
@@ -165,7 +169,8 @@ module Ev_loop = struct
   type t = {
     timer: Timer.t;
     actions: Action_queue.t;
-    io_tbl: IO_tbl.t;  (** Used for select *)
+    io_tbl: IO_tbl.t;
+        (** Used to remember which events are tracked on which FD *)
     in_blocking_section: bool A.t;
         (** Is the ev loop thread currently waiting? *)
     pipe_read: Unix.file_descr;  (** Main thread only *)
@@ -181,7 +186,6 @@ module Ev_loop = struct
     Unix.set_nonblock pipe_read;
 
     let poll = Poll.create () in
-    Poll.set poll pipe_read Poll.Event.read;
 
     {
       timer = Timer.create ();
@@ -233,14 +237,18 @@ module Ev_loop = struct
     let delay_s = Option.value delay_s ~default:10. in
     let timeout = Poll.Timeout.after Int64.(of_float (delay_s *. 1e9)) in
 
-    (* run [select] *)
+    (* poll *)
+    Poll.set self.poll self.pipe_read Poll.Event.read;
     A.set self.in_blocking_section true;
+
     let has_events =
-      let@ _sp = Tracing_.with_span "moonpool-unix.evloop.select" in
+      let@ _sp = Tracing_.with_span "moonpool-unix.evloop.poll" in
+      Printf.eprintf "polling…\n%!";
       match Poll.wait self.poll timeout with
       | `Timeout -> false
       | `Ok -> true
     in
+    Printf.eprintf "poll returned with has_events=%b\n%!" has_events;
 
     A.set self.in_blocking_section false;
 
@@ -269,6 +277,10 @@ let rec get_or_set_as_current_ (ev : Ev_loop.t) : Ev_loop.t * bool =
 
 let bg_loop_ (ev_loop : Ev_loop.t) =
   let@ _sp = Tracing_.with_span "Moonpool_unix.bg-loop" in
+  Printf.eprintf "bg loop is thread %d\n%!" (Thread.id @@ Thread.self ());
+  ignore
+    (Unix.sigprocmask Unix.SIG_BLOCK [ Sys.sigpipe; Sys.sigterm; Sys.sigint ]
+      : _ list);
   while true do
     Ev_loop.run_step_ ev_loop
   done
diff --git a/test/io/echo_server.ml b/test/io/echo_server.ml
index da2c30c2..b964c214 100644
--- a/test/io/echo_server.ml
+++ b/test/io/echo_server.ml
@@ -11,10 +11,14 @@ let main ~port ~j () : unit =
   let@ _main_runner = MU.main in
   Trace.set_thread_name "main";
 
+  Printf.eprintf "main is thread %d\n%!" (Thread.id @@ Thread.self ());
+
   let@ server =
     MU.TCP_server.with_server ~runner (MU.Sockaddr.any port)
       ~handle:(fun ~client_addr:addr ic oc ->
         Trace.message "got new client";
+        Printf.eprintf "handle client on thread %d\n%!"
+          (Thread.id @@ Thread.self ());
         let@ _sp =
           Trace.with_span ~__FILE__ ~__LINE__ "handle.client" ~data:(fun () ->
               [ "addr", `String (MU.Sockaddr.show addr) ])
@@ -59,4 +63,7 @@ let () =
   in
   Arg.parse opts ignore "echo server";
 
-  main ~port:!port ~j:!j ()
+  try main ~port:!port ~j:!j ()
+  with Sys.Break ->
+    Printf.eprintf "got ctrl-c, exiting\n%!";
+    exit 0