diff --git a/lib/rack/handler/puma.rb b/lib/rack/handler/puma.rb
index b493aead..ef1a2a7f 100644
--- a/lib/rack/handler/puma.rb
+++ b/lib/rack/handler/puma.rb
@@ -42,10 +42,12 @@ module Rack
             user_config.threads min, max
           end
 
-          host = options[:Host] || default_options[:Host]
-          port = options[:Port] || default_options[:Port]
+          if options[:Host] || options[:Port]
+            host = options[:Host] || default_options[:Host]
+            port = options[:Port] || default_options[:Port]
+            self.set_host_port_to_config(host, port, user_config)
+          end
 
-          self.set_host_port_to_config(host, port, user_config)
           self.set_host_port_to_config(default_options[:Host], default_options[:Port], default_config)
 
           user_config.app app