diff --git a/mrbgems/mruby-dir/mrblib/dir.rb b/mrbgems/mruby-dir/mrblib/dir.rb
index 829962bd9..e6c2bf755 100644
--- a/mrbgems/mruby-dir/mrblib/dir.rb
+++ b/mrbgems/mruby-dir/mrblib/dir.rb
@@ -1,4 +1,6 @@
 class Dir
+  include Enumerable
+
   def each(&block)
     while s = self.read
       block.call(s)