diff --git a/README.md b/README.md
index 31ea47d..67eeb3f 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
+# WORK IN PROGRESS
+
+Not ready for use.
+
 [![Crate release version](https://flat.badgen.net/crates/v/process-wrap)](https://crates.io/crates/process-wrap)
 [![Crate license: Apache 2.0 or MIT](https://flat.badgen.net/badge/license/Apache%202.0%20or%20MIT)][copyright]
 [![CI status](https://github.com/watchexec/process-wrap/actions/workflows/test.yml/badge.svg)](https://github.com/watchexec/process-wrap/actions/workflows/test.yml)