diff --git a/tests/unit/dune b/tests/unit/dune
index 4aa1fc95..bb3c8960 100644
--- a/tests/unit/dune
+++ b/tests/unit/dune
@@ -1,4 +1,4 @@
 (tests
- (names t_util t_buf t_server t_io)
+ (names t_util t_buf t_server t_io t_response)
  (package tiny_httpd)
  (libraries tiny_httpd.core qcheck-core qcheck-core.runner test_util))
diff --git a/tests/unit/t_response.ml b/tests/unit/t_response.ml
new file mode 100644
index 00000000..2df31cb8
--- /dev/null
+++ b/tests/unit/t_response.ml
@@ -0,0 +1,17 @@
+open Test_util
+open Tiny_httpd_core
+module U = Util
+
+let () =
+  let res =
+    Response.make_raw ~code:200 ~headers:[ "content-length", "42" ] ""
+  in
+  let h = Headers.get_exn "content-length" res.headers in
+  assert_eq "42" h
+
+let () =
+  let res =
+    Response.make_raw ~code:200 ~headers:[ "Content-Length", "42" ] ""
+  in
+  let h = Headers.get_exn "content-length" res.headers in
+  assert_eq "42" h