diff --git a/History.txt b/History.txt
index 9669c3b5..abb845e7 100644
--- a/History.txt
+++ b/History.txt
@@ -5,6 +5,7 @@ Improvements:
 * Ruby 1.9 early compatbility: Merged commits form Eric Wong and Matt Aimonetti.
 * Better RubyGems support thanks to added env she-bang to mongrel_rails executable.
 * Smartly load http11 extension using fat-binary approach.
+* Better detection of Windows platform (usage of RbConfig::CONFIG instead of RUBY_PLATFORM)
 
 Bugfixes:
 
diff --git a/bin/mongrel_rails b/bin/mongrel_rails
index 92e57abc..ea3839b4 100644
--- a/bin/mongrel_rails
+++ b/bin/mongrel_rails
@@ -138,7 +138,7 @@ module Mongrel
       config.join
 
       if config.needs_restart
-        if RUBY_PLATFORM !~ /mswin/
+        unless RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
           cmd = "ruby #{__FILE__} start #{original_args.join(' ')}"
           config.log "Restarting with arguments:  #{cmd}"
           config.stop(false, true)
diff --git a/lib/mongrel/configurator.rb b/lib/mongrel/configurator.rb
index b251c7f9..d07de1e9 100644
--- a/lib/mongrel/configurator.rb
+++ b/lib/mongrel/configurator.rb
@@ -81,7 +81,7 @@ module Mongrel
 
     # Writes the PID file if we're not on Windows.
     def write_pid_file
-      if RUBY_PLATFORM !~ /mingw|mswin/
+      unless RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
         log "Writing PID file to #{@pid_file}"
         open(@pid_file,"w") {|f| f.write(Process.pid) }
         open(@pid_file,"w") do |f|
@@ -185,7 +185,7 @@ module Mongrel
     def daemonize(options={})
       ops = resolve_defaults(options)
       # save this for later since daemonize will hose it
-      if RUBY_PLATFORM !~ /mingw|mswin/
+      unless RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
         require 'daemons/daemonize'
 
         logfile = ops[:log_file]
@@ -366,7 +366,7 @@ module Mongrel
       # clean up the pid file always
       at_exit { remove_pid_file }
 
-      if RUBY_PLATFORM !~ /mingw|mswin/
+      unless RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
         # graceful shutdown
         trap("TERM") { log "TERM signal received."; stop }
         trap("USR1") { log "USR1 received, toggling $mongrel_debug_client to #{!$mongrel_debug_client}"; $mongrel_debug_client = !$mongrel_debug_client }
diff --git a/lib/mongrel/rails.rb b/lib/mongrel/rails.rb
index 39a2c7db..54bb830b 100644
--- a/lib/mongrel/rails.rb
+++ b/lib/mongrel/rails.rb
@@ -173,7 +173,7 @@ module Mongrel
         ops = resolve_defaults(options)
         setup_signals(options)
 
-        if RUBY_PLATFORM !~ /mingw|mswin/
+        unless RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
           # rails reload
           trap("HUP") { log "HUP signal received."; reload!          }
 
diff --git a/test/testhelp.rb b/test/testhelp.rb
index f4d1a3c8..90127cce 100644
--- a/test/testhelp.rb
+++ b/test/testhelp.rb
@@ -67,5 +67,5 @@ end
 
 # Platform check helper ;-)
 def windows?
-  result = RUBY_PLATFORM =~ /mingw|mswin/
+  @windows ||= RbConfig::CONFIG['host_os'] =~ /mingw|mswin/
 end