diff --git a/README.md b/README.md
index 688d9193..407eefcc 100644
--- a/README.md
+++ b/README.md
@@ -101,7 +101,7 @@ Now start up the database container.
 make start-db
 ```
 
-Import external data from [OpenStreetMapData](http://osmdata.openstreetmap.de/), [Natural Earth](http://www.naturalearthdata.com/) and [OpenStreetMap Lake Labels](https://github.com/lukasmartinelli/osm-lakelines).
+Import external data from [OpenStreetMapData](http://osmdata.openstreetmap.de/), [Natural Earth](http://www.naturalearthdata.com/) and [OpenStreetMap Lake Labels](https://github.com/lukasmartinelli/osm-lakelines). Natural Earth country boundaries are used in the few lowest zoom levels.
 
 ```bash
 make import-data