diff --git a/README.md b/README.md
index 511095c..135b175 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,9 @@
 [![Tests](https://github.com/simonw/dclient/workflows/Test/badge.svg)](https://github.com/simonw/dclient/actions?query=workflow%3ATest)
 [![License](https://img.shields.io/badge/license-Apache%202.0-blue.svg)](https://github.com/simonw/dclient/blob/master/LICENSE)
 
-A client CLI utility for [Datasette](https://datasette.io/) instances
+A client CLI utility for [Datasette](https://datasette.io/) instances.
+
+Much of the functionality requires Datasette 1.0a2 or higher.
 
 ## Things you can do with dclient
 
@@ -49,4 +51,4 @@ pip install -e '.[test]'
 To run the tests:
 ```bash
 pytest
-```
\ No newline at end of file
+```