diff --git a/README.md b/README.md
index ffe933b..0608aaf 100644
--- a/README.md
+++ b/README.md
@@ -5,10 +5,11 @@
 [![Build Status](https://github.com/trevorblades/countries/workflows/Node%20CI/badge.svg)](https://github.com/trevorblades/countries/actions)
 [![Contributor Covenant](https://img.shields.io/badge/Contributor%20Covenant-v2.0%20adopted-ff69b4.svg)](CODE_OF_CONDUCT.md)
 
-A public GraphQL API for information about countries, continents, and languages. This project uses [Countries List](https://annexare.github.io/Countries/) as a data source, so the schema follows the shape of that data, with a few exceptions:
+A public GraphQL API for information about countries, continents, and languages. This project uses [Countries List](https://annexare.github.io/Countries/) and [`provinces`](https://github.com/substack/provinces) as data sources, so the schema follows the shape of that data, with a few exceptions:
 
 1. The codes used to key the objects in the original data are available as a `code` property on each item returned from the API.
 2. The `continent` and `languages` properties are now objects and arrays of objects, respectively.
+3. Each `Country` has an array of `states` populated by their states/provinces, if any.
 
 ## Writing queries