diff --git a/lib/puma/server.rb b/lib/puma/server.rb
index b46c8c4f..2ddb5f73 100644
--- a/lib/puma/server.rb
+++ b/lib/puma/server.rb
@@ -328,7 +328,7 @@ module Puma
           client.write body
           client.flush
         else
-          res-body.each do |part|
+          res_body.each do |part|
             client.write part
             client.flush
           end