diff --git a/Gemfile b/Gemfile
index 965cc72ae..fc6143075 100644
--- a/Gemfile
+++ b/Gemfile
@@ -12,5 +12,5 @@ gem 'asciidoctor-pdf', '1.6.0'
 gem 'coderay', '1.1.3'
 gem 'pygments.rb', '2.2.0'
 gem 'thread_safe', '0.3.6'
-gem 'epubcheck-ruby', '4.2.5.0'
+gem 'epubcheck-ruby', '5.0.0.0'
 gem 'html-proofer', '3.19.2'