diff --git a/README.md b/README.md
index 4f6df02..ea9109a 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,6 @@
 # gomatrix
 [![GoDoc](https://godoc.org/github.com/matrix-org/gomatrix?status.svg)](https://godoc.org/github.com/matrix-org/gomatrix)
 
-A Golang Matrix client
+A Golang Matrix client.
+
+**THIS IS UNDER ACTIVE DEVELOPMENT: BREAKING CHANGES ARE FREQUENT.**