diff --git a/lib/irb/cmd/fork.rb b/lib/irb/cmd/fork.rb
deleted file mode 100644
index 1cd235997fbaaf..00000000000000
--- a/lib/irb/cmd/fork.rb
+++ /dev/null
@@ -1,34 +0,0 @@
-# frozen_string_literal: false
-#
-#   fork.rb -
-#   	by Keiju ISHITSUKA(keiju@ruby-lang.org)
-#
-
-require_relative "nop"
-
-module IRB
-  # :stopdoc:
-
-  module ExtendCommand
-    class Fork < Nop
-      def execute
-        pid = __send__ ExtendCommand.irb_original_method_name("fork")
-        unless pid
-          class << self
-            alias_method :exit, ExtendCommand.irb_original_method_name('exit')
-          end
-          if block_given?
-            begin
-              yield
-            ensure
-              exit
-            end
-          end
-        end
-        pid
-      end
-    end
-  end
-
-  # :startdoc:
-end