diff --git a/lib/cool.io/listener.rb b/lib/cool.io/listener.rb
index <HASH>..<HASH> 100644
--- a/lib/cool.io/listener.rb
+++ b/lib/cool.io/listener.rb
@@ -59,6 +59,9 @@ module Coolio
     else
       def on_readable
         begin
+          # In Windows, accept_nonblock() with multiple processes
+          # causes thundering herd problem.
+          # To avoid this, we need to use accept().
           on_connection @listen_socket.accept
         rescue Errno::EAGAIN, Errno::ECONNABORTED
         end
Add comment for why to use accept in Windows