diff --git a/mrbgems/mruby-socket/mrblib/socket.rb b/mrbgems/mruby-socket/mrblib/socket.rb
index bca07e72b..cbda5c183 100644
--- a/mrbgems/mruby-socket/mrblib/socket.rb
+++ b/mrbgems/mruby-socket/mrblib/socket.rb
@@ -570,8 +570,4 @@ class UNIXServer < UNIXSocket
   end
 end
 
-class Socket
-  include Constants
-end
-
 class SocketError < StandardError; end
diff --git a/mrbgems/mruby-socket/src/socket.c b/mrbgems/mruby-socket/src/socket.c
index e1110dfc7..0fcdd2afc 100644
--- a/mrbgems/mruby-socket/src/socket.c
+++ b/mrbgems/mruby-socket/src/socket.c
@@ -1082,6 +1082,8 @@ mrb_mruby_socket_gem_init(mrb_state* mrb)
   } while (0)
 
 #include "const.cstub"
+
+  mrb_include_module(mrb, sock, constants);
 }
 
 void