diff --git a/README.Rmd b/README.Rmd
index 25c9478..51c2b6b 100644
--- a/README.Rmd
+++ b/README.Rmd
@@ -30,6 +30,8 @@
 remotes::install_git("https://korap.ids-mannheim.de/gerrit/IDS-Mannheim/revealjs")
 ```
 
+> **Package renamed — migration note:** This package, the IDS corporate design fork of [rstudio/revealjs](https://github.com/rstudio/revealjs), was called `revealjs` before version 0.9.1.9009 and was renamed to `revealjs.ids` so that it can be installed alongside the upstream package. To migrate existing documents, replace `revealjs::revealjs_presentation` with `revealjs.ids::revealjs_presentation` in the YAML header. (Alternatively, install upstream `revealjs` and keep the old header for documents that should use the upstream format.)
+
 To create a [reveal.js](https://revealjs.com/) presentation from R Markdown you specify the `revealjs_presentation` output format in the front-matter of your document. You can create a slide show broken up into sections by using the `#` and `##` heading tags (you can also create a new slide without a header using a horizontal rule (`----`). For example here's a simple slide show:
 
 ``` markdown