diff --git a/Project.toml b/Project.toml
index 56cc41b..acfc0ac 100644
--- a/Project.toml
+++ b/Project.toml
@@ -11,3 +11,4 @@ Reexport = "189a3867-3050-52da-a836-e630ba90ab69"
 [compat]
 CBinding = "0.9"
 Reexport = "0.2"
+julia = "1.5"
diff --git a/README.md b/README.md
index 2beeaff..f019aae 100644
--- a/README.md
+++ b/README.md
@@ -6,7 +6,6 @@
 <!-- [![Codecov](https://codecov.io/gh/trixi-framework/P4est.jl/branch/master/graph/badge.svg)](https://codecov.io/gh/trixi-framework/P4est.jl) -->
 <!-- [![Coveralls](https://coveralls.io/repos/github/trixi-framework/P4est.jl/badge.svg?branch=master)](https://coveralls.io/github/trixi-framework/P4est.jl?branch=master) -->
 [![License: MIT](https://img.shields.io/badge/License-MIT-success.svg)](https://opensource.org/licenses/MIT)
-<!-- [![GitHub commits since tagged version](https://img.shields.io/github/commits-since/trixi-framework/P4est.jl/v0.2.0.svg?style=social&logo=github)](https://github.com/trixi-framework/P4est.jl) -->
 
 **P4est.jl** is a Julia package that wraps
 [p4est](https://github.com/cburstedde/p4est), a C library to manage multiple