diff --git a/README.md b/README.md
index 95b5b1e..ae66b71 100644
--- a/README.md
+++ b/README.md
@@ -17,6 +17,8 @@ The toy has an internal lithium-ion battery that can be charged via USB-C and pr
 It can also be monitored and controlled via Home Assistant or with a web interface in local network.
 It is privacy-friendly: it works completely localy and sends no data to any external service.
 
+> Disclaimer: this is a prototype and its design may change substantially at any time. If you plan on building one, please start from the last tagged commit (e.g. `1.0.1` and take note of the tag for future references.
+
 ## How does it work?
 
 ![Take apart](images/take_apart.jpg)