diff --git a/Gemfile b/Gemfile
index 965cc72ae..414dbd917 100644
--- a/Gemfile
+++ b/Gemfile
@@ -3,7 +3,7 @@ source 'https://rubygems.org'
 gem 'rake', '13.0.3'
 gem 'asciidoctor', '2.0.15'
 
-gem 'json', '2.5.1'
+gem 'json', '2.6.3'
 gem 'awesome_print', '1.9.2'
 
 gem 'asciidoctor-epub3', '1.5.1'