diff --git a/tellstick/README.md b/tellstick/README.md
index 24b498b..ca8be04 100644
--- a/tellstick/README.md
+++ b/tellstick/README.md
@@ -1,5 +1,11 @@
 # Home Assistant Add-on: TellStick
 
+> [!CAUTION]
+> **Deprecation notice**
+> The library this add-on depends on is abandoned. Its last activity was 5
+> years ago and it cannot be built on Alpine versions above 3.15. Users can continue
+> using the add-on, but no issues or pull requests will be accepted.
+
 TellStick and TellStick Duo service.
 
 ![Supports aarch64 Architecture][aarch64-shield] ![Supports amd64 Architecture][amd64-shield] ![Supports armhf Architecture][armhf-shield] ![Supports armv7 Architecture][armv7-shield] ![Supports i386 Architecture][i386-shield]
@@ -21,4 +27,4 @@ For more details, please check the TellStick [protocol list][protocol-list].
 [amd64-shield]: https://img.shields.io/badge/amd64-yes-green.svg
 [armhf-shield]: https://img.shields.io/badge/armhf-yes-green.svg
 [armv7-shield]: https://img.shields.io/badge/armv7-yes-green.svg
-[i386-shield]: https://img.shields.io/badge/i386-yes-green.svg
\ No newline at end of file
+[i386-shield]: https://img.shields.io/badge/i386-yes-green.svg