diff --git a/README.md b/README.md
index 2aa161e..23df4a1 100644
--- a/README.md
+++ b/README.md
@@ -5,7 +5,7 @@ functionality to [Isabelle](https://isabelle.in.tum.de) or showcase
 specific functionality. The individual hacks usually consist out of 
 a single theory file and all documentation is contained in that 
 theory file. The master branch should work with the latest official 
-release of Isabelle (Isabelle 2019, at time of writing), hacks for 
+release of Isabelle (Isabelle 2020, at time of writing), hacks for 
 older versions might be available on a dedicated branch.
 
 ## List of Isabelle Hacks