diff --git a/mrbgems/mruby-struct/mrblib/struct.rb b/mrbgems/mruby-struct/mrblib/struct.rb
index 2439e2a37..f80c54518 100644
--- a/mrbgems/mruby-struct/mrblib/struct.rb
+++ b/mrbgems/mruby-struct/mrblib/struct.rb
@@ -3,6 +3,7 @@
 #
 # ISO 15.2.18
 class Struct
+  include Enumerable
 
   ##
   # Calls the given block for each element of +self+