diff --git a/.ruby-version b/.ruby-version
new file mode 100644
index 0000000000..50e47c89ca
--- /dev/null
+++ b/.ruby-version
@@ -0,0 +1 @@
+3.1.1
\ No newline at end of file
diff --git a/Gemfile b/Gemfile
index 019af18d2e..c1d2754bd5 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,5 +1,7 @@
 source 'https://rubygems.org'
 
+ruby '3.1.1'
+
 gem 'github-pages', group: :jekyll_plugins
 gem 'webrick'