diff --git a/ext/tk/lib/tk.rb b/ext/tk/lib/tk.rb
index 907f602da5..dca4b8892e 100644
--- a/ext/tk/lib/tk.rb
+++ b/ext/tk/lib/tk.rb
@@ -3089,6 +3089,7 @@ module TkConfigMethod
 end
 
 class TkObject<TkKernel
+  extend  TkCore
   include Tk
   include TkConfigMethod
   include TkBindCore