diff --git a/openxml-package.gemspec b/openxml-package.gemspec
index bf3bfc1..724957c 100644
--- a/openxml-package.gemspec
+++ b/openxml-package.gemspec
@@ -19,13 +19,14 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_dependency "rubyzip", "~> 2.3"
+  spec.add_dependency "rubyzip", ">= 2.3", "< 4.0"
   spec.add_dependency "nokogiri"
   spec.add_dependency "ox"
 
   spec.add_development_dependency "bundler"
   spec.add_development_dependency "rake"
-  spec.add_development_dependency "minitest"
+  spec.add_development_dependency "minitest", "~> 6.0"
+  spec.add_development_dependency "minitest-mock", "~> 5.27"
   spec.add_development_dependency "minitest-reporters"
   spec.add_development_dependency "minitest-reporters-turn_reporter"
   spec.add_development_dependency "pry"
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 5958bce..7dcb1d2 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -8,6 +8,7 @@
 
 require "rr"
 
+require "minitest/mock"
 require "minitest/reporters/turn_reporter"
 Minitest::Reporters.use! Minitest::Reporters::TurnReporter.new