diff --git a/foreman_maintain.gemspec b/foreman_maintain.gemspec
index 6403494ec..738050ddf 100644
--- a/foreman_maintain.gemspec
+++ b/foreman_maintain.gemspec
@@ -25,7 +25,7 @@ the Foreman/Satellite up and running."
   s.add_dependency 'highline'
 
   s.add_development_dependency 'bundler', '>= 1.17'
-  s.add_development_dependency 'minitest'
+  s.add_development_dependency 'minitest', '~> 5.0'
   s.add_development_dependency 'minitest-reporters'
   s.add_development_dependency 'minitest-stub-const'
   s.add_development_dependency 'mocha'
diff --git a/test/definitions/features/installer_test.rb b/test/definitions/features/installer_test.rb
index aa253f84f..9f453dc44 100644
--- a/test/definitions/features/installer_test.rb
+++ b/test/definitions/features/installer_test.rb
@@ -57,7 +57,7 @@
     end
 
     it 'has no config file' do
-      _(subject.config_file).must_equal(nil)
+      _(subject.config_file).must_be_nil
     end
   end
 end
diff --git a/test/lib/cli/plugin_command_test.rb b/test/lib/cli/plugin_command_test.rb
index 8018869db..2f4466efd 100644
--- a/test/lib/cli/plugin_command_test.rb
+++ b/test/lib/cli/plugin_command_test.rb
@@ -33,7 +33,7 @@ module ForemanMaintain
 
       it 'runs purge-puppet' do
         Cli::PluginCommand.any_instance.expects(:run_scenario).with do |scenario|
-          _(scenario.context.get(:remove_data)).must_equal nil
+          _(scenario.context.get(:remove_data)).must_be_nil
           _(scenario.label).must_equal :puppet_disable
         end
         run_cmd