diff --git a/Gemfile b/Gemfile
index 1d5342c..cbbc677 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,6 +2,8 @@
 
 source "https://rubygems.org"
 
+ruby '2.7'
+
 gem "jekyll-theme-chirpy", "~> 6.1"
 
 group :test do