diff --git a/cohttp-async/bin/cohttp_curl_async.ml b/cohttp-async/bin/cohttp_curl_async.ml
index 3d2125b0a8..526254ea75 100644
--- a/cohttp-async/bin/cohttp_curl_async.ml
+++ b/cohttp-async/bin/cohttp_curl_async.ml
@@ -39,7 +39,7 @@ let _ =
   Logs.set_level @@ Some Logs.Debug;
   Logs.set_reporter (Logs_fmt.reporter ());
   let open Command.Spec in
-  Command.async ~summary:"Fetch URL and print it"
+  Command.async_spec ~summary:"Fetch URL and print it"
     (empty
      +> anon ("url" %: string)
      +> flag "-X" (optional_with_default "GET" string)
diff --git a/cohttp-async/bin/cohttp_server_async.ml b/cohttp-async/bin/cohttp_server_async.ml
index 4d1cab4f29..8e808ad940 100644
--- a/cohttp-async/bin/cohttp_server_async.ml
+++ b/cohttp-async/bin/cohttp_server_async.ml
@@ -120,14 +120,14 @@ let start_server docroot port index cert_file key_file verbose () =
         Logs.err (fun f -> f "Error from %s" (Socket.Address.to_string addr));
         Logs.err (fun f -> f "%s" @@ Exn.to_string exn)))
     ~mode
-    (Tcp.on_port port)
+    (Tcp.Where_to_listen.of_port port)
     (handler ~info ~docroot ~index) >>= fun _serv ->
   Deferred.never ()
 
 let () =
   let open Command in
   run @@
-  async ~summary:"Serve the local directory contents via HTTP or HTTPS"
+  async_spec ~summary:"Serve the local directory contents via HTTP or HTTPS"
     Spec.(
       empty
       +> anon (maybe_with_default "." ("docroot" %: string))