diff --git a/mrbgems/stdlib.gembox b/mrbgems/stdlib.gembox
index a4d01af1a..e10792ecb 100644
--- a/mrbgems/stdlib.gembox
+++ b/mrbgems/stdlib.gembox
@@ -46,6 +46,9 @@ MRuby::GemBox.new do |conf|
   # Use Enumerator::Lazy class (require mruby-enumerator)
   conf.gem :core => "mruby-enum-lazy"
 
+  # Use Enumerator::Chain class (require mruby-enumerator)
+  conf.gem :core => "mruby-enum-chain"
+
   # Use toplevel object (main) methods extension
   conf.gem :core => "mruby-toplevel-ext"