diff --git a/.rubocop.yml b/.rubocop.yml
index 0798cf7..5f3dda8 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,4 +1,5 @@
 AllCops:
+  TargetRubyVersion: 2.4+
   DisplayCopNames: true
   Exclude:
     - 'db/**/*.rb'
@@ -33,6 +34,10 @@ Style/Documentation:
 Layout/LineLength:
   Enabled: false
 
+Metrics/BlockLength:
+  Max: 50
+  IgnoredMethods: ['describe', 'context']
+
 Metrics/MethodLength:
   Enabled: false
 
@@ -92,6 +97,9 @@ Style/GuardClause:
   Exclude:
     - 'spec/support/remote_ip_monkey_patch.rb'
 
+Lint/DuplicateMethods:
+  Enabled: false
+
 # Offense count: 2
 Lint/ShadowingOuterLocalVariable:
   Exclude:
diff --git a/spec/sony_ci_api/client_spec.rb b/spec/sony_ci_api/client_spec.rb
index f8a2d2a..eae4663 100644
--- a/spec/sony_ci_api/client_spec.rb
+++ b/spec/sony_ci_api/client_spec.rb
@@ -19,6 +19,20 @@ def stub_request_and_call_block(http_method, path, with: {}, stub_response: {})
   return_val
 end
 
+# Create some dummy class available in a global scope that can be
+# recognized by ERB within SonyCiApi::Client#load_config!
+class TestCredentials
+  def self.config_hash
+    @config_hash ||= {
+      username: rand(9999).to_s,
+      password: rand(9999).to_s,
+      workspace_id: rand(9999).to_s,
+      client_id: rand(9999).to_s,
+      client_secret: rand(9999).to_s
+    }
+  end
+end
+
 RSpec.describe SonyCiApi::Client do
   def randhex(len = 32)
     len.times.map { rand(15).to_s(16) }.join
@@ -530,20 +544,6 @@ def camelize_params(**params)
       valid_config_file.write(config_hash.to_yaml) && valid_config_file.rewind
       valid_config_file_erb.write(config_hash_with_erb.to_yaml) && valid_config_file_erb.rewind
       invalid_config_file.write(':') && invalid_config_file.rewind
-
-      # Create some dummy class available in a global scope that can be
-      # recognized by ERB within SonyCiApi::Client#load_config!
-      class TestCredentials
-        def self.config_hash
-          @config_hash ||= {
-            username: rand(9999).to_s,
-            password: rand(9999).to_s,
-            workspace_id: rand(9999).to_s,
-            client_id: rand(9999).to_s,
-            client_secret: rand(9999).to_s
-          }
-        end
-      end
     end
 
     after do
diff --git a/spec/sony_ci_api/error_spec.rb b/spec/sony_ci_api/error_spec.rb
index 19b341a..7af7b03 100644
--- a/spec/sony_ci_api/error_spec.rb
+++ b/spec/sony_ci_api/error_spec.rb
@@ -32,7 +32,7 @@
         expected_mappings.each do |faraday_error_class, expected_error_class|
           # Create an instance of the Faraday error class. Use nil message and
           # empty response because we don't need those, but Faraday classes do.
-          faraday_error = faraday_error_class.new(nil, {})
+          faraday_error_class.new(nil, {})
           new_error = described_class.create_from(faraday_error_class.new(nil, {}))
           expect(new_error).to be_a expected_error_class
         end