diff --git a/Gemfile b/Gemfile
index 51d7f5d..7363638 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 gem "github-markup", "4.0.1"
 gem "RedCloth", "=4.3.2"
 gem "asciidoctor", "2.0.18"
-gem "commonmarker", "=0.21.0"
+gem "commonmarker", "0.23.9"
 gem "creole", "=0.5.0"
 gem "org-ruby", "=0.9.12"
 gem "rdoc", "6.3.2"