diff --git a/Gemfile b/Gemfile
index 746544262..980261bc9 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', '~> 4.12.0'
+  gem 'mini_magick', '~> 4.13.0'
 end
 
 # Optional Markdown support