diff --git a/.circleci/config.yml b/.circleci/config.yml
index bee1780..c978096 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -45,9 +45,9 @@ commands:
       - restore_cache:
           name: Restoring Gem Cache
           keys:
-            - &cache-key gem-cache-v5-{{ checksum "<< parameters.path >>/<< parameters.gemspec-file >>" }}-<< parameters.ruby-image >>
-            - gem-cache-v5-{{ checksum "<< parameters.path >>/<< parameters.gemspec-file >>" }}
-            - gem-cache-v5-
+            - &cache-key gem-cache-v4-{{ checksum "<< parameters.path >>/<< parameters.gemspec-file >>" }}-<< parameters.ruby-image >>
+            - gem-cache-v4-{{ checksum "<< parameters.path >>/<< parameters.gemspec-file >>" }}
+            - gem-cache-v4-
       - run:
           name: Install dependencies
           command: |
diff --git a/apis/influxdb-client-apis.gemspec b/apis/influxdb-client-apis.gemspec
index 4b28ced..d32faac 100644
--- a/apis/influxdb-client-apis.gemspec
+++ b/apis/influxdb-client-apis.gemspec
@@ -49,7 +49,7 @@ Gem::Specification.new do |spec|
   spec.add_runtime_dependency 'typhoeus', '~> 1.0', '>= 1.0.1'
 
   spec.add_development_dependency 'bundler', '~> 2.0'
-  spec.add_development_dependency 'minitest', '~> 5.0'
+  spec.add_development_dependency 'minitest', '5.15.0'
   spec.add_development_dependency 'minitest-reporters', '~> 1.4'
   spec.add_development_dependency 'rake', '~> 13.0'
   spec.add_development_dependency 'rubocop', '~> 0.66.0'
diff --git a/test/influxdb/default_api_test.rb b/test/influxdb/default_api_test.rb
index e05049c..b01dca8 100644
--- a/test/influxdb/default_api_test.rb
+++ b/test/influxdb/default_api_test.rb
@@ -18,7 +18,6 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-require 'minitest/autorun'
 require 'test_helper'
 require 'influxdb2/client/default_api'
 
diff --git a/test/test_helper.rb b/test/test_helper.rb
index 6e56c74..7fdd8d9 100644
--- a/test/test_helper.rb
+++ b/test/test_helper.rb
@@ -18,7 +18,6 @@
 # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 # THE SOFTWARE.
 
-require 'minitest/autorun'
 require 'simplecov'
 SimpleCov.start do
   add_filter 'lib/influxdb2/client/models/'
@@ -33,8 +32,8 @@
 $LOAD_PATH.unshift File.expand_path('../lib', __dir__)
 require 'influxdb-client'
 
-require 'minitest/reporters'
 require 'minitest/autorun'
+require 'minitest/reporters'
 Minitest::Reporters.use! unless ENV['RM_INFO']
 
 require 'webmock/minitest'