diff --git a/lib/webrick/httprequest.rb b/lib/webrick/httprequest.rb
index 2b9f3f2f47..a25c9933c5 100644
--- a/lib/webrick/httprequest.rb
+++ b/lib/webrick/httprequest.rb
@@ -185,7 +185,7 @@ module WEBrick
       meta["REQUEST_URI"]       = @request_uri.to_s
       meta["SCRIPT_NAME"]       = @script_name.dup
       meta["SERVER_NAME"]       = @host
-      meta["SERVER_PORT"]       = @port
+      meta["SERVER_PORT"]       = @port.to_s
       meta["SERVER_PROTOCOL"]   = "HTTP/" + @config[:HTTPVersion].to_s
       meta["SERVER_SOFTWARE"]   = @config[:ServerSoftware].dup