diff --git a/README.md b/README.md
index 7ef3bd8..4db59ce 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,8 @@
 [![GitHub contributors](https://img.shields.io/github/contributors/thegeeklab/hugo-geekblog)](https://github.com/thegeeklab/hugo-geekblog/graphs/contributors)
 [![License: MIT](https://img.shields.io/github/license/thegeeklab/hugo-geekblog)](https://github.com/thegeeklab/hugo-geekblog/blob/main/LICENSE)
 
+> **Important:** We have switched to 'main' as default branch. The 'master' branch is no longer maintained and will be removed after June 30, 2021!
+
 Geekblog is a simple Hugo theme for personal blogs. It is intentionally designed as a fast and lean theme and may not fit the requirements of complex websites. If a more feature-complete theme is required there are a lot of got alternatives out there. You can find a demo and the full documentation at [https://hugo-geekblog.geekdocs.de](https://hugo-geekblog.geekdocs.de).
 
 ![Desktop and mobile preview](https://github.com/thegeeklab/hugo-geekblog/blob/main/images/readme.png)