diff --git a/lib/watchr.rb b/lib/watchr.rb
index 3d0b4f4..630f3df 100644
--- a/lib/watchr.rb
+++ b/lib/watchr.rb
@@ -108,7 +108,7 @@ def debug(msg)
     #
     def handler
       @handler ||=
-        case ENV['HANDLER'] || Config::CONFIG['host_os']
+        case ENV['HANDLER'] || RbConfig::CONFIG['host_os']
           when /darwin|mach|osx|fsevents?/i
             if Watchr::HAVE_FSE
               Watchr::EventHandler::Darwin