1 files changed, 5 insertions, 3 deletions
diff --git a/lib/delegate.rb b/lib/delegate.rb
index f4068f1b32..970bb9d342 100644
--- a/lib/delegate.rb
+++ b/lib/delegate.rb
@@ -115,9 +115,10 @@
 # implementation, see SimpleDelegator.
 #
 class Delegator
-  preserved = [:__id__, :object_id, :__send__, :public_send, :respond_to?, :send,
-               :instance_eval, :instance_exec,
-              ]
+  preserved = [
+    :__id__, :object_id, :__send__, :public_send, :respond_to?, :send,
+    :instance_eval, :instance_exec, :extend,
+  ]
   instance_methods.each do |m|
     next if preserved.include?(m)
     undef_method m
@@ -267,6 +268,7 @@ def DelegateClass(superclass)
     :__id__, :object_id, :__send__, :public_send, :respond_to?, :send,
     :==, :equal?, :initialize, :method_missing, :__getobj__, :__setobj__,
     :clone, :dup, :marshal_dump, :marshal_load, :instance_eval, :instance_exec,
+    :extend,
   ]
   klass.module_eval {
     include Delegator::MethodDelegation