diff --git a/Gemfile b/Gemfile
index db3558068..c87e3aabd 100644
--- a/Gemfile
+++ b/Gemfile
@@ -41,7 +41,7 @@ end
 
 # Optional gem for exporting the gantt to a PNG file
 group :minimagick do
-  gem 'mini_magick', '~> 5.0.1'
+  gem 'mini_magick', '~> 5.1.0'
 end
 
 # Optional CommonMark support, not for JRuby