set version
diff --git a/site/Gemfile b/site/Gemfile
index d4101ce..389bc22 100644
--- a/site/Gemfile
+++ b/site/Gemfile
@@ -19,6 +19,7 @@
 gem 'jekyll', '= 3.9.0'
 #gem 'jekyll', '2.4.0'
 
+gem 'jekyll', '= 3.9.0'
 gem 'github-pages'
 gem 'rouge'
 gem 'jekyll-oembed', :require => 'jekyll_oembed'