diff --git a/README.md b/README.md
index 38cbb22..3b3d1c0 100644
--- a/README.md
+++ b/README.md
@@ -351,6 +351,7 @@ The response for a request contains the following information.
   statusText: 'OK',
 
   // `headers` the headers that the server responded with
+  // All header names are lower cased
   headers: {},
 
   // `config` is the config that was provided to `axios` for the request