diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 52c1e0b0..5391ffac 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -31,6 +31,7 @@ jobs:
           - 2.5
           - 2.6
           - 2.7
+          - 3.0
         gemfile:
           - gemfiles/standalone.gemfile
           - gemfiles/openssl.gemfile
diff --git a/.rspec b/.rspec
index 4e1e0d2f..3687797e 100644
--- a/.rspec
+++ b/.rspec
@@ -1 +1,2 @@
+--require spec_helper
 --color
diff --git a/.rubocop.yml b/.rubocop.yml
index dbd8a04b..09abda53 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,8 @@
 inherit_from: .rubocop_todo.yml
 
+AllCops:
+  TargetRubyVersion: 2.1
+
 Layout/AlignParameters:
   EnforcedStyle: with_fixed_indentation
 
diff --git a/.ebert.yml b/.sourcelevel.yml
similarity index 90%
rename from .ebert.yml
rename to .sourcelevel.yml
index 25e7a344..b3315650 100644
--- a/.ebert.yml
+++ b/.sourcelevel.yml
@@ -6,7 +6,7 @@ engines:
     enabled: true
   rubocop:
     enabled: true
-    channel: rubocop-0-49
+    channel: rubocop-0-52
   duplication:
     config:
       languages:
diff --git a/README.md b/README.md
index 9850b9fc..510df1d2 100644
--- a/README.md
+++ b/README.md
@@ -525,10 +525,11 @@ We depend on [Bundler](http://rubygems.org/gems/bundler) for defining gemspec an
 rake release
 ```
 
-The tests are written with rspec. Given you have installed the dependencies via bundler, you can run tests with
+The tests are written with rspec. [Appraisal](https://github.com/thoughtbot/appraisal) is used to ensure compatibility with 3rd party dependencies providing cryptographic features.
 
 ```bash
-bundle exec rspec
+bundle install
+bundle exec appraisal rake test
 ```
 
 **If you want a release cut with your PR, please include a version bump according to [Semantic Versioning](http://semver.org/)**
diff --git a/Rakefile b/Rakefile
index 727c38a9..d641df1c 100644
--- a/Rakefile
+++ b/Rakefile
@@ -1,11 +1,14 @@
+require 'bundler/setup'
 require 'bundler/gem_tasks'
 
 begin
   require 'rspec/core/rake_task'
+  require 'rubocop/rake_task'
 
   RSpec::Core::RakeTask.new(:test)
+  RuboCop::RakeTask.new(:rubocop)
 
-  task default: :test
+  task default: %i[rubocop test]
 rescue LoadError
   puts 'RSpec rake tasks not available. Please run "bundle install" to install missing dependencies.'
 end
diff --git a/gemfiles/openssl.gemfile b/gemfiles/openssl.gemfile
index 94ce8660..7b269727 100644
--- a/gemfiles/openssl.gemfile
+++ b/gemfiles/openssl.gemfile
@@ -2,6 +2,7 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 0.52.0"
 gem "openssl", "~> 2.1"
 
 gemspec path: "../"
diff --git a/gemfiles/rbnacl.gemfile b/gemfiles/rbnacl.gemfile
index ad523a89..c1f3d686 100644
--- a/gemfiles/rbnacl.gemfile
+++ b/gemfiles/rbnacl.gemfile
@@ -2,6 +2,7 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 0.52.0"
 gem "rbnacl"
 
 gemspec path: "../"
diff --git a/gemfiles/standalone.gemfile b/gemfiles/standalone.gemfile
index 095e6608..02bc57bd 100644
--- a/gemfiles/standalone.gemfile
+++ b/gemfiles/standalone.gemfile
@@ -2,4 +2,6 @@
 
 source "https://rubygems.org"
 
+gem "rubocop", "~> 0.52.0"
+
 gemspec path: "../"
diff --git a/ruby-jwt.gemspec b/ruby-jwt.gemspec
index a0415b7d..946e8e77 100644
--- a/ruby-jwt.gemspec
+++ b/ruby-jwt.gemspec
@@ -27,5 +27,4 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'simplecov', '< 0.18'
   spec.add_development_dependency 'simplecov-json'
   spec.add_development_dependency 'codeclimate-test-reporter'
-  spec.add_development_dependency 'codacy-coverage'
 end
diff --git a/spec/integration/readme_examples_spec.rb b/spec/integration/readme_examples_spec.rb
index 7488541c..7b50a0d8 100644
--- a/spec/integration/readme_examples_spec.rb
+++ b/spec/integration/readme_examples_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../spec_helper'
-require 'jwt'
-
-describe 'README.md code test' do
+RSpec.describe 'README.md code test' do
   context 'algorithm usage' do
     let(:payload) { { data: 'test' } }
 
@@ -79,7 +76,7 @@
         { 'data' => 'test' },
         { 'alg' => 'PS256' }
       ]
-    end if OpenSSL::VERSION >= '2.1'
+    end if ::Gem::Version.new(OpenSSL::VERSION) >= ::Gem::Version.new('2.1')
   end
 
   context 'claims' do
diff --git a/spec/jwk/decode_with_jwk_spec.rb b/spec/jwk/decode_with_jwk_spec.rb
index c16e85b2..3e8ccfe4 100644
--- a/spec/jwk/decode_with_jwk_spec.rb
+++ b/spec/jwk/decode_with_jwk_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../spec_helper'
-require 'jwt'
-
-describe JWT do
+RSpec.describe JWT do
   describe '.decode for JWK usecase' do
     let(:keypair)       { OpenSSL::PKey::RSA.new(2048) }
     let(:jwk)           { JWT::JWK.new(keypair) }
diff --git a/spec/jwk/ec_spec.rb b/spec/jwk/ec_spec.rb
index 08050880..3a949766 100644
--- a/spec/jwk/ec_spec.rb
+++ b/spec/jwk/ec_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../spec_helper'
-require 'jwt'
-
-describe JWT::JWK::EC do
+RSpec.describe JWT::JWK::EC do
   let(:ec_key) { OpenSSL::PKey::EC.new("secp384r1").generate_key }
 
   describe '.new' do
diff --git a/spec/jwk/hmac_spec.rb b/spec/jwk/hmac_spec.rb
index 31ad4ee0..d7594077 100644
--- a/spec/jwk/hmac_spec.rb
+++ b/spec/jwk/hmac_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../spec_helper'
-require 'jwt'
-
-describe JWT::JWK::HMAC do
+RSpec.describe JWT::JWK::HMAC do
   let(:hmac_key) { 'secret-key' }
 
   describe '.new' do
diff --git a/spec/jwk/rsa_spec.rb b/spec/jwk/rsa_spec.rb
index 4b6c9274..d5cc37e8 100644
--- a/spec/jwk/rsa_spec.rb
+++ b/spec/jwk/rsa_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require_relative '../spec_helper'
-require 'jwt'
-
-describe JWT::JWK::RSA do
+RSpec.describe JWT::JWK::RSA do
   let(:rsa_key) { OpenSSL::PKey::RSA.new(2048) }
 
   describe '.new' do
diff --git a/spec/jwk_spec.rb b/spec/jwk_spec.rb
index 277eedfa..1fc606f0 100644
--- a/spec/jwk_spec.rb
+++ b/spec/jwk_spec.rb
@@ -1,9 +1,6 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
-require 'jwt'
-
-describe JWT::JWK do
+RSpec.describe JWT::JWK do
   let(:rsa_key) { OpenSSL::PKey::RSA.new(2048) }
   let(:ec_key) { OpenSSL::PKey::EC.new("secp384r1").generate_key }
 
diff --git a/spec/jwt/claims_validator_spec.rb b/spec/jwt/claims_validator_spec.rb
index 06d707a1..e2908879 100644
--- a/spec/jwt/claims_validator_spec.rb
+++ b/spec/jwt/claims_validator_spec.rb
@@ -1,5 +1,4 @@
-require 'spec_helper'
-require 'jwt/claims_validator'
+# frozen_string_literal: true
 
 RSpec.describe JWT::ClaimsValidator do
   let(:validator) { described_class.new(claims) }
diff --git a/spec/jwt/verify_spec.rb b/spec/jwt/verify_spec.rb
index a434a171..3cb763ac 100644
--- a/spec/jwt/verify_spec.rb
+++ b/spec/jwt/verify_spec.rb
@@ -1,229 +1,224 @@
 # frozen_string_literal: true
 
-require 'spec_helper'
-require 'jwt/verify'
-
-module JWT # rubocop:disable Metrics/ModuleLength
-  RSpec.describe Verify do
-    let(:base_payload) { { 'user_id' => 'some@user.tld' } }
-    let(:options) { { leeway: 0 } }
+RSpec.describe ::JWT::Verify do
+  let(:base_payload) { { 'user_id' => 'some@user.tld' } }
+  let(:options) { { leeway: 0 } }
+
+  context '.verify_aud(payload, options)' do
+    let(:scalar_aud) { 'ruby-jwt-aud' }
+    let(:array_aud) { %w[ruby-jwt-aud test-aud ruby-ruby-ruby] }
+    let(:scalar_payload) { base_payload.merge('aud' => scalar_aud) }
+    let(:array_payload) { base_payload.merge('aud' => array_aud) }
+
+    it 'must raise JWT::InvalidAudError when the singular audience does not match' do
+      expect do
+        described_class.verify_aud(scalar_payload, options.merge(aud: 'no-match'))
+      end.to raise_error JWT::InvalidAudError
+    end
 
-    context '.verify_aud(payload, options)' do
-      let(:scalar_aud) { 'ruby-jwt-aud' }
-      let(:array_aud) { %w[ruby-jwt-aud test-aud ruby-ruby-ruby] }
-      let(:scalar_payload) { base_payload.merge('aud' => scalar_aud) }
-      let(:array_payload) { base_payload.merge('aud' => array_aud) }
+    it 'must raise JWT::InvalidAudError when the payload has an array and none match the supplied value' do
+      expect do
+        described_class.verify_aud(array_payload, options.merge(aud: 'no-match'))
+      end.to raise_error JWT::InvalidAudError
+    end
 
-      it 'must raise JWT::InvalidAudError when the singular audience does not match' do
-        expect do
-          Verify.verify_aud(scalar_payload, options.merge(aud: 'no-match'))
-        end.to raise_error JWT::InvalidAudError
-      end
+    it 'must allow a matching singular audience to pass' do
+      described_class.verify_aud(scalar_payload, options.merge(aud: scalar_aud))
+    end
 
-      it 'must raise JWT::InvalidAudError when the payload has an array and none match the supplied value' do
-        expect do
-          Verify.verify_aud(array_payload, options.merge(aud: 'no-match'))
-        end.to raise_error JWT::InvalidAudError
-      end
+    it 'must allow an array with any value matching the one in the options' do
+      described_class.verify_aud(array_payload, options.merge(aud: array_aud.first))
+    end
 
-      it 'must allow a matching singular audience to pass' do
-        Verify.verify_aud(scalar_payload, options.merge(aud: scalar_aud))
-      end
+    it 'must allow an array with any value matching any value in the options array' do
+      described_class.verify_aud(array_payload, options.merge(aud: array_aud))
+    end
 
-      it 'must allow an array with any value matching the one in the options' do
-        Verify.verify_aud(array_payload, options.merge(aud: array_aud.first))
-      end
+    it 'must allow a singular audience payload matching any value in the options array' do
+      described_class.verify_aud(scalar_payload, options.merge(aud: array_aud))
+    end
+  end
 
-      it 'must allow an array with any value matching any value in the options array' do
-        Verify.verify_aud(array_payload, options.merge(aud: array_aud))
-      end
+  context '.verify_expiration(payload, options)' do
+    let(:payload) { base_payload.merge('exp' => (Time.now.to_i - 5)) }
 
-      it 'must allow a singular audience payload matching any value in the options array' do
-        Verify.verify_aud(scalar_payload, options.merge(aud: array_aud))
-      end
+    it 'must raise JWT::ExpiredSignature when the token has expired' do
+      expect do
+        described_class.verify_expiration(payload, options)
+      end.to raise_error JWT::ExpiredSignature
     end
 
-    context '.verify_expiration(payload, options)' do
-      let(:payload) { base_payload.merge('exp' => (Time.now.to_i - 5)) }
+    it 'must allow some leeway in the expiration when global leeway is configured' do
+      described_class.verify_expiration(payload, options.merge(leeway: 10))
+    end
 
-      it 'must raise JWT::ExpiredSignature when the token has expired' do
-        expect do
-          Verify.verify_expiration(payload, options)
-        end.to raise_error JWT::ExpiredSignature
-      end
+    it 'must allow some leeway in the expiration when exp_leeway is configured' do
+      described_class.verify_expiration(payload, options.merge(exp_leeway: 10))
+    end
 
-      it 'must allow some leeway in the expiration when global leeway is configured' do
-        Verify.verify_expiration(payload, options.merge(leeway: 10))
-      end
+    it 'must be expired if the exp claim equals the current time' do
+      payload['exp'] = Time.now.to_i
 
-      it 'must allow some leeway in the expiration when exp_leeway is configured' do
-        Verify.verify_expiration(payload, options.merge(exp_leeway: 10))
-      end
+      expect do
+        described_class.verify_expiration(payload, options)
+      end.to raise_error JWT::ExpiredSignature
+    end
 
-      it 'must be expired if the exp claim equals the current time' do
-        payload['exp'] = Time.now.to_i
+    context 'when leeway is not specified' do
+      let(:options) { {} }
 
+      it 'used a default leeway of 0' do
         expect do
-          Verify.verify_expiration(payload, options)
+          described_class.verify_expiration(payload, options)
         end.to raise_error JWT::ExpiredSignature
       end
+    end
+  end
 
-      context 'when leeway is not specified' do
-        let(:options) { {} }
+  context '.verify_iat(payload, options)' do
+    let(:iat) { Time.now.to_f }
+    let(:payload) { base_payload.merge('iat' => iat) }
 
-        it 'used a default leeway of 0' do
-          expect do
-            Verify.verify_expiration(payload, options)
-          end.to raise_error JWT::ExpiredSignature
-        end
-      end
+    it 'must allow a valid iat' do
+      described_class.verify_iat(payload, options)
     end
 
-    context '.verify_iat(payload, options)' do
-      let(:iat) { Time.now.to_f }
-      let(:payload) { base_payload.merge('iat' => iat) }
+    it 'must ignore configured leeway' do
+      expect{described_class.verify_iat(payload.merge('iat' => (iat + 60)), options.merge(leeway: 70)) }
+        .to raise_error(JWT::InvalidIatError)
+    end
 
-      it 'must allow a valid iat' do
-        Verify.verify_iat(payload, options)
-      end
+    it 'must properly handle integer times' do
+      described_class.verify_iat(payload.merge('iat' => Time.now.to_i), options)
+    end
 
-      it 'must ignore configured leeway' do
-        expect{Verify.verify_iat(payload.merge('iat' => (iat + 60)), options.merge(leeway: 70)) }
-          .to raise_error(JWT::InvalidIatError)
-      end
+    it 'must raise JWT::InvalidIatError when the iat value is not Numeric' do
+      expect do
+        described_class.verify_iat(payload.merge('iat' => 'not a number'), options)
+      end.to raise_error JWT::InvalidIatError
+    end
 
-      it 'must properly handle integer times' do
-        Verify.verify_iat(payload.merge('iat' => Time.now.to_i), options)
-      end
+    it 'must raise JWT::InvalidIatError when the iat value is in the future' do
+      expect do
+        described_class.verify_iat(payload.merge('iat' => (iat + 120)), options)
+      end.to raise_error JWT::InvalidIatError
+    end
+  end
 
-      it 'must raise JWT::InvalidIatError when the iat value is not Numeric' do
+  context '.verify_iss(payload, options)' do
+    let(:iss) { 'ruby-jwt-gem' }
+    let(:payload) { base_payload.merge('iss' => iss) }
+
+    let(:invalid_token) { JWT.encode base_payload, payload[:secret] }
+
+    context 'when iss is a String' do
+      it 'must raise JWT::InvalidIssuerError when the configured issuer does not match the payload issuer' do
         expect do
-          Verify.verify_iat(payload.merge('iat' => 'not a number'), options)
-        end.to raise_error JWT::InvalidIatError
+          described_class.verify_iss(payload, options.merge(iss: 'mismatched-issuer'))
+        end.to raise_error JWT::InvalidIssuerError
       end
 
-      it 'must raise JWT::InvalidIatError when the iat value is in the future' do
+      it 'must raise JWT::InvalidIssuerError when the payload does not include an issuer' do
         expect do
-          Verify.verify_iat(payload.merge('iat' => (iat + 120)), options)
-        end.to raise_error JWT::InvalidIatError
+          described_class.verify_iss(base_payload, options.merge(iss: iss))
+        end.to raise_error(JWT::InvalidIssuerError, /received <none>/)
       end
-    end
-
-    context '.verify_iss(payload, options)' do
-      let(:iss) { 'ruby-jwt-gem' }
-      let(:payload) { base_payload.merge('iss' => iss) }
-
-      let(:invalid_token) { JWT.encode base_payload, payload[:secret] }
-
-      context 'when iss is a String' do
-        it 'must raise JWT::InvalidIssuerError when the configured issuer does not match the payload issuer' do
-          expect do
-            Verify.verify_iss(payload, options.merge(iss: 'mismatched-issuer'))
-          end.to raise_error JWT::InvalidIssuerError
-        end
 
-        it 'must raise JWT::InvalidIssuerError when the payload does not include an issuer' do
-          expect do
-            Verify.verify_iss(base_payload, options.merge(iss: iss))
-          end.to raise_error(JWT::InvalidIssuerError, /received <none>/)
-        end
-
-        it 'must allow a matching issuer to pass' do
-          Verify.verify_iss(payload, options.merge(iss: iss))
-        end
+      it 'must allow a matching issuer to pass' do
+        described_class.verify_iss(payload, options.merge(iss: iss))
+      end
+    end
+    context 'when iss is an Array' do
+      it 'must raise JWT::InvalidIssuerError when no matching issuers in array' do
+        expect do
+          described_class.verify_iss(payload, options.merge(iss: %w[first second]))
+        end.to raise_error JWT::InvalidIssuerError
       end
-      context 'when iss is an Array' do
-        it 'must raise JWT::InvalidIssuerError when no matching issuers in array' do
-          expect do
-            Verify.verify_iss(payload, options.merge(iss: %w[first second]))
-          end.to raise_error JWT::InvalidIssuerError
-        end
 
-        it 'must raise JWT::InvalidIssuerError when the payload does not include an issuer' do
-          expect do
-            Verify.verify_iss(base_payload, options.merge(iss: %w[first second]))
-          end.to raise_error(JWT::InvalidIssuerError, /received <none>/)
-        end
+      it 'must raise JWT::InvalidIssuerError when the payload does not include an issuer' do
+        expect do
+          described_class.verify_iss(base_payload, options.merge(iss: %w[first second]))
+        end.to raise_error(JWT::InvalidIssuerError, /received <none>/)
+      end
 
-        it 'must allow an array with matching issuer to pass' do
-          Verify.verify_iss(payload, options.merge(iss: ['first', iss, 'third']))
-        end
+      it 'must allow an array with matching issuer to pass' do
+        described_class.verify_iss(payload, options.merge(iss: ['first', iss, 'third']))
       end
     end
+  end
 
-    context '.verify_jti(payload, options)' do
-      let(:payload) { base_payload.merge('jti' => 'some-random-uuid-or-whatever') }
+  context '.verify_jti(payload, options)' do
+    let(:payload) { base_payload.merge('jti' => 'some-random-uuid-or-whatever') }
 
-      it 'must allow any jti when the verfy_jti key in the options is truthy but not a proc' do
-        Verify.verify_jti(payload, options.merge(verify_jti: true))
-      end
+    it 'must allow any jti when the verfy_jti key in the options is truthy but not a proc' do
+      described_class.verify_jti(payload, options.merge(verify_jti: true))
+    end
 
-      it 'must raise JWT::InvalidJtiError when the jti is missing' do
-        expect do
-          Verify.verify_jti(base_payload, options)
-        end.to raise_error JWT::InvalidJtiError, /missing/i
-      end
+    it 'must raise JWT::InvalidJtiError when the jti is missing' do
+      expect do
+        described_class.verify_jti(base_payload, options)
+      end.to raise_error JWT::InvalidJtiError, /missing/i
+    end
 
-      it 'must raise JWT::InvalidJtiError when the jti is an empty string' do
-        expect do
-          Verify.verify_jti(base_payload.merge('jti' => '   '), options)
-        end.to raise_error JWT::InvalidJtiError, /missing/i
-      end
+    it 'must raise JWT::InvalidJtiError when the jti is an empty string' do
+      expect do
+        described_class.verify_jti(base_payload.merge('jti' => '   '), options)
+      end.to raise_error JWT::InvalidJtiError, /missing/i
+    end
 
-      it 'must raise JWT::InvalidJtiError when verify_jti proc returns false' do
-        expect do
-          Verify.verify_jti(payload, options.merge(verify_jti: ->(_jti) { false }))
-        end.to raise_error JWT::InvalidJtiError, /invalid/i
-      end
+    it 'must raise JWT::InvalidJtiError when verify_jti proc returns false' do
+      expect do
+        described_class.verify_jti(payload, options.merge(verify_jti: ->(_jti) { false }))
+      end.to raise_error JWT::InvalidJtiError, /invalid/i
+    end
 
-      it 'true proc should not raise JWT::InvalidJtiError' do
-        Verify.verify_jti(payload, options.merge(verify_jti: ->(_jti) { true }))
-      end
+    it 'true proc should not raise JWT::InvalidJtiError' do
+      described_class.verify_jti(payload, options.merge(verify_jti: ->(_jti) { true }))
+    end
 
-      it 'it should not throw arguement error with 2 args' do
-        expect do
-          Verify.verify_jti(payload, options.merge(verify_jti: ->(_jti, pl) {
-            true
-          }))
-        end.to_not raise_error
-      end
-      it 'should have payload as second param in proc' do
-        Verify.verify_jti(payload, options.merge(verify_jti: ->(_jti, pl) {
-          expect(pl).to eq(payload)
+    it 'it should not throw arguement error with 2 args' do
+      expect do
+        described_class.verify_jti(payload, options.merge(verify_jti: ->(_jti, pl) {
+          true
         }))
-      end
+      end.to_not raise_error
     end
+    it 'should have payload as second param in proc' do
+      described_class.verify_jti(payload, options.merge(verify_jti: ->(_jti, pl) {
+        expect(pl).to eq(payload)
+      }))
+    end
+  end
 
-    context '.verify_not_before(payload, options)' do
-      let(:payload) { base_payload.merge('nbf' => (Time.now.to_i + 5)) }
+  context '.verify_not_before(payload, options)' do
+    let(:payload) { base_payload.merge('nbf' => (Time.now.to_i + 5)) }
 
-      it 'must raise JWT::ImmatureSignature when the nbf in the payload is in the future' do
-        expect do
-          Verify.verify_not_before(payload, options)
-        end.to raise_error JWT::ImmatureSignature
-      end
+    it 'must raise JWT::ImmatureSignature when the nbf in the payload is in the future' do
+      expect do
+        described_class.verify_not_before(payload, options)
+      end.to raise_error JWT::ImmatureSignature
+    end
 
-      it 'must allow some leeway in the token age when global leeway is configured' do
-        Verify.verify_not_before(payload, options.merge(leeway: 10))
-      end
+    it 'must allow some leeway in the token age when global leeway is configured' do
+      described_class.verify_not_before(payload, options.merge(leeway: 10))
+    end
 
-      it 'must allow some leeway in the token age when nbf_leeway is configured' do
-        Verify.verify_not_before(payload, options.merge(nbf_leeway: 10))
-      end
+    it 'must allow some leeway in the token age when nbf_leeway is configured' do
+      described_class.verify_not_before(payload, options.merge(nbf_leeway: 10))
     end
+  end
 
-    context '.verify_sub(payload, options)' do
-      let(:sub) { 'ruby jwt subject' }
+  context '.verify_sub(payload, options)' do
+    let(:sub) { 'ruby jwt subject' }
 
-      it 'must raise JWT::InvalidSubError when the subjects do not match' do
-        expect do
-          Verify.verify_sub(base_payload.merge('sub' => 'not-a-match'), options.merge(sub: sub))
-        end.to raise_error JWT::InvalidSubError
-      end
+    it 'must raise JWT::InvalidSubError when the subjects do not match' do
+      expect do
+        described_class.verify_sub(base_payload.merge('sub' => 'not-a-match'), options.merge(sub: sub))
+      end.to raise_error JWT::InvalidSubError
+    end
 
-      it 'must allow a matching sub' do
-        Verify.verify_sub(base_payload.merge('sub' => sub), options.merge(sub: sub))
-      end
+    it 'must allow a matching sub' do
+      described_class.verify_sub(base_payload.merge('sub' => sub), options.merge(sub: sub))
     end
 
     context '.verify_claims' do
@@ -242,12 +237,12 @@ module JWT # rubocop:disable Metrics/ModuleLength
       %w[verify_aud verify_expiration verify_iat verify_iss verify_jti verify_not_before verify_sub].each do |method|
         let(:payload) { base_payload.merge(fail_verifications_payload) }
         it "must skip verification when #{method} option is set to false" do
-          Verify.verify_claims(payload, options.merge(method => false))
+          described_class.verify_claims(payload, options.merge(method => false))
         end
 
         it "must raise error when #{method} option is set to true" do
           expect do
-            Verify.verify_claims(payload, options.merge(method => true).merge(fail_verifications_options))
+            described_class.verify_claims(payload, options.merge(method => true).merge(fail_verifications_options))
           end.to raise_error
         end
       end
diff --git a/spec/jwt_spec.rb b/spec/jwt_spec.rb
index a5e5f3d6..fbf86a94 100644
--- a/spec/jwt_spec.rb
+++ b/spec/jwt_spec.rb
@@ -1,9 +1,6 @@
-require 'spec_helper'
-require 'jwt'
-require 'jwt/encode'
-require 'jwt/decode'
+# frozen_string_literal: true
 
-describe JWT do
+RSpec.describe JWT do
   let(:payload) { { 'user_id' => 'some@user.tld' } }
 
   let :data do
@@ -263,7 +260,7 @@
     end
   end
 
-  unless OpenSSL::VERSION >= '2.1'
+  unless ::Gem::Version.new(OpenSSL::VERSION) >= ::Gem::Version.new('2.1')
     %w[PS256 PS384 PS512].each do |alg|
       context "alg: #{alg}" do
         it 'raises error about OpenSSL version' do
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index a6ecae86..c16ebf54 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -1,28 +1,26 @@
+# frozen_string_literal: true
+
 require 'rspec'
 require 'simplecov'
 require 'simplecov-json'
 require 'codeclimate-test-reporter'
-require 'codacy-coverage'
-
-Codacy::Reporter.start
 
-SimpleCov.configure do
+SimpleCov.start do
   root File.join(File.dirname(__FILE__), '..')
   project_name 'Ruby JWT - Ruby JSON Web Token implementation'
   add_filter 'spec'
 end
 
-SimpleCov.start if ENV['COVERAGE']
+require 'jwt'
 
 CERT_PATH = File.join(File.dirname(__FILE__), 'fixtures', 'certs')
 
 RSpec.configure do |config|
   config.expect_with :rspec do |c|
-    c.syntax = %i[should expect]
+    c.syntax = :expect
   end
 
   config.run_all_when_everything_filtered = true
   config.filter_run :focus
-
   config.order = 'random'
 end