diff --git a/lib/webrick/server.rb b/lib/webrick/server.rb
index 01976febd3..fd6b7a61b5 100644
--- a/lib/webrick/server.rb
+++ b/lib/webrick/server.rb
@@ -100,7 +100,7 @@ module WEBrick
       @logger.info("ruby #{rubyv}")
 
       @listeners = []
-      @shutdown_pipe = @config[:ShutdownPipe]
+      @shutdown_pipe = nil
       unless @config[:DoNotListen]
         raise ArgumentError, "Port must an integer" unless @config[:Port].to_s == @config[:Port].to_i.to_s