diff --git a/Gemfile b/Gemfile
index 1cec18c2..16346a6b 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,7 +1,7 @@
 source 'https://rubygems.org'
 
 gem 'rake', '13.0.6'
-gem 'asciidoctor', '2.0.20'
+gem 'asciidoctor', '2.0.21'
 
 gem 'json', '2.6.3'
 gem 'awesome_print', '1.9.2'