diff --git a/README.md b/README.md
index 29ff331..6e46878 100644
--- a/README.md
+++ b/README.md
@@ -430,9 +430,6 @@ For a more elaborated example on how to use this library, please check [lsl](htt
 ---
 
 ## Contact Us
-For **questions** or **general comments** regarding the use of this library,
-please use our public [hipchat room](http://inaka.net/hipchat).
-
 If you find any **bugs** or have a **problem** while using this library, please
 [open an issue](https://github.com/inaka/sumo_rest/issues/new) in this repo
 (or a pull request :)).
diff --git a/src/sr_request.erl b/src/sr_request.erl
index a0acad8..0043659 100644
--- a/src/sr_request.erl
+++ b/src/sr_request.erl
@@ -13,9 +13,12 @@
 
 -type binding_name() :: id | atom().
 
+-type http_header_name_lowercase() :: binary().
+-type http_header() :: {http_header_name_lowercase(), iodata()}.
+
 -opaque req() ::
   #{ body     := sr_json:json()
-   , headers  := [{binary(), iodata()}]
+   , headers  := [http_header()]
    , path     := binary()
    , bindings := #{binding_name() => any()}
    }.
@@ -44,7 +47,7 @@ from_cowboy(CowboyReq) ->
 body(#{body := Body}) ->
   Body.
 
--spec headers(req()) -> [{binary(), iodata()}].
+-spec headers(req()) -> [http_header()].
 headers(#{headers := Headers}) ->
   Headers.