diff --git a/test/hello.ru b/test/hello.ru
index 3162ff79..deb8fc82 100644
--- a/test/hello.ru
+++ b/test/hello.ru
@@ -1 +1 @@
-run lambda { |env| [200, {}, ["Hello World"]] }
+run lambda { |env| [200, {"Content-Type" => "text/plain"}, ["Hello World"]] }