diff --git a/Gemfile b/Gemfile
index 8f4c67cd2693a3014810906173edc8d7c15afe8f..84962395ef81f97c4b7fd50daa0b82f582023bbf 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,7 +12,7 @@ gem "jekyll", "~> 4.0"
 gem "bundler", "> 2.0"
 
 gem "minima", "~> 2.5"
-gem 'jekyll-theme-lcsb-default', '~> 0.4.7'
+gem 'jekyll-theme-lcsb-default', '~> 0.4.21'
 
 # If you want to use GitHub Pages, remove the "gem "jekyll"" above and
 # uncomment the line below. To upgrade, run `bundle update github-pages`.