diff --git a/.gitignore b/.gitignore
index c93c0b18..5e84e6f2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ Gemfile.lock
 .buildpath
 *~
 vendor/
+.DS_Store
diff --git a/github-markup.gemspec b/github-markup.gemspec
index 4818706d..260df18c 100644
--- a/github-markup.gemspec
+++ b/github-markup.gemspec
@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
   s.require_paths = %w[lib]
 
   s.add_development_dependency 'rake', '~> 12'
-  s.add_development_dependency 'activesupport', '~> 4.0'
+  s.add_development_dependency 'activesupport', '~> 7.1.3.4'
   s.add_development_dependency 'minitest', '~> 5.4', '>= 5.4.3'
   s.add_development_dependency 'html-pipeline', '~> 1.0'
   s.add_development_dependency 'sanitize', '>= 4.6.3'