diff --git a/Project.toml b/Project.toml
index 8fff7c05..694d79a2 100644
--- a/Project.toml
+++ b/Project.toml
@@ -1,7 +1,7 @@
 name = "KnuthBendix"
 uuid = "c2604015-7b3d-4a30-8a26-9074551ec60a"
 authors = ["Marek Kaluba <kalmar@amu.edu.pl>", "Mikołaj Pabiszczak <mikolaj.pabiszczak@gmail.com>"]
-version = "0.5.0"
+version = "0.4.0"
 
 [deps]
 MacroTools = "1914dd2f-81c6-5fcd-8719-6d5c9610ff09"