diff --git a/Gemfile b/Gemfile
index 0893f08a..e145809e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 gem 'rake', '13.2.1'
 gem 'asciidoctor', '2.0.22'
 
-gem 'json', '2.9.1'
+gem 'json', '2.15.2'
 gem 'awesome_print', '1.9.2'
 
 gem 'asciidoctor-fb2', '0.7.0'