diff --git a/lib/cached_resource/configuration.rb b/lib/cached_resource/configuration.rb
index 272664e..4e5d556 100644
--- a/lib/cached_resource/configuration.rb
+++ b/lib/cached_resource/configuration.rb
@@ -69,7 +69,8 @@ def concurrent_write=(value)
 
     def require_concurrent_ruby
       begin
-        send :require, 'concurrent/promise'
+        # send :require, 'concurrent/promise'
+        require 'concurrent/promise'
       rescue LoadError
         @cached_resource.logger.error(
           "`concurrent_write` option is enabled, but `concurrent-ruby` is not an installed dependency"