diff --git a/Gemfile b/Gemfile
index 4af120842..bb77a60a6 100644
--- a/Gemfile
+++ b/Gemfile
@@ -2,8 +2,10 @@ source "https://rubygems.org"
 ruby RUBY_VERSION
 
 gem "i18n"
+gem "logger", "~> 1.5.0"
+gem "jekyll", "~> 4.2.1"
 
 group :jekyll_plugins do
-    gem "jekyll-rdf"
+    gem "jekyll-rdf", "4.0.4"
     gem "jekyll-include-cache"
 end