diff --git a/spinach.gemspec b/spinach.gemspec
index 331cfa4..ddc73ce 100644
--- a/spinach.gemspec
+++ b/spinach.gemspec
@@ -17,7 +17,7 @@ Gem::Specification.new do |gem|
   gem.add_development_dependency 'capybara'
   gem.add_development_dependency 'pry'
   gem.add_development_dependency 'rspec'
-  gem.add_development_dependency 'minitest', '< 5.0'
+  gem.add_development_dependency 'minitest', '<= 5.21.2'
   gem.add_development_dependency 'fakefs', ">= 0.5.2"
 
   gem.required_ruby_version = Gem::Requirement.new(">= 2.4".freeze)