diff --git a/README.md b/README.md
index 6ea2f4a..5c851fe 100644
--- a/README.md
+++ b/README.md
@@ -315,6 +315,11 @@ properties and methods:
 * `origin` - The 'origin' for the request, for example:
    `http://my-api:8008`.
 * `absoluteUrl` - The absolute URL for the request.
+* `ip()` - Returns the ip address of the client. This may be ipv4 or ipv6.
+  If `CURVEBALL_TRUSTPROXY` is set in the environment and truthy, this will
+  use the information from the `X-Forwarded-For` header (if available).
+
+
 
 ### The Response interface
 
diff --git a/changelog.md b/changelog.md
index 5a4a4be..003b09d 100644
--- a/changelog.md
+++ b/changelog.md
@@ -16,6 +16,8 @@ Changelog
   `Response` classes now have an extra constructor argument. This means
   if you ever manually constructed any of these, there's a small change
   you'll need to make. Typescript should point all these problems!
+* If `CURVEBALL_TRUSTPROXY` is set, `request.ip()` will trust proxies
+  by default, and return the ip of the real client instead of the proxy.
 
 
 0.18.0 (2022-04-16)