diff --git a/.rubocop.yml b/.rubocop.yml
index f5ccbfa9e..d2b062843 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,17 +1,13 @@
 inherit_from: .rubocop_todo.yml
 
 require:
-  - rubocop-inclusivity
   - rubocop-packaging
   - rubocop-performance
 
 AllCops:
   DisplayCopNames: true
   DisplayStyleGuide: true
-  TargetRubyVersion: 2.4
-
-Inclusivity/Race:
-  Enabled: true
+  TargetRubyVersion: 2.6
 
 Metrics/BlockLength:
   Exclude:
@@ -60,3 +56,146 @@ Style/IfUnlessModifier:
 Style/SlicingWithRange: # (0.83)
   Enabled: true
 
+Layout/BeginEndAlignment: # (new in 0.91)
+  Enabled: true
+Lint/BinaryOperatorWithIdenticalOperands: # (new in 0.89)
+  Enabled: true
+Lint/ConstantDefinitionInBlock: # (new in 0.91)
+  Enabled: true
+Lint/DuplicateElsifCondition: # (new in 0.88)
+  Enabled: true
+Lint/DuplicateRequire: # (new in 0.90)
+  Enabled: true
+Lint/DuplicateRescueException: # (new in 0.89)
+  Enabled: true
+Lint/EmptyConditionalBody: # (new in 0.89)
+  Enabled: true
+Lint/EmptyFile: # (new in 0.90)
+  Enabled: true
+Lint/FloatComparison: # (new in 0.89)
+  Enabled: true
+Lint/HashCompareByIdentity: # (new in 0.93)
+  Enabled: true
+Lint/IdentityComparison: # (new in 0.91)
+  Enabled: true
+Lint/MissingSuper: # (new in 0.89)
+  Enabled: true
+Lint/MixedRegexpCaptureTypes: # (new in 0.85)
+  Enabled: true
+Lint/OutOfRangeRegexpRef: # (new in 0.89)
+  Enabled: true
+Lint/RedundantSafeNavigation: # (new in 0.93)
+  Enabled: true
+Lint/SelfAssignment: # (new in 0.89)
+  Enabled: true
+Lint/TopLevelReturnWithArgument: # (new in 0.89)
+  Enabled: true
+Lint/TrailingCommaInAttributeDeclaration: # (new in 0.90)
+  Enabled: true
+Performance/BlockGivenWithExplicitBlock: # (new in 1.9)
+  Enabled: true
+Performance/CollectionLiteralInLoop: # (new in 1.8)
+  Enabled: true
+Performance/ConstantRegexp: # (new in 1.9)
+  Enabled: true
+Performance/MethodObjectAsBlock: # (new in 1.9)
+  Enabled: true
+Performance/RedundantEqualityComparisonBlock: # (new in 1.10)
+  Enabled: true
+Performance/RedundantSortBlock: # (new in 1.7)
+  Enabled: true
+Performance/RedundantSplitRegexpArgument: # (new in 1.10)
+  Enabled: true
+Performance/RedundantStringChars: # (new in 1.7)
+  Enabled: true
+Performance/ReverseFirst: # (new in 1.7)
+  Enabled: true
+Performance/SortReverse: # (new in 1.7)
+  Enabled: true
+Performance/Squeeze: # (new in 1.7)
+  Enabled: true
+Performance/StringInclude: # (new in 1.7)
+  Enabled: true
+Performance/Sum: # (new in 1.8)
+  Enabled: true
+
+Gemspec/DateAssignment: # (new in 1.10)
+  Enabled: true
+Layout/LineEndStringConcatenationIndentation: # (new in 1.18)
+  Enabled: true
+Layout/SpaceBeforeBrackets: # (new in 1.7)
+  Enabled: true
+Lint/AmbiguousAssignment: # (new in 1.7)
+  Enabled: true
+Lint/AmbiguousRange: # (new in 1.19)
+  Enabled: true
+Lint/DeprecatedConstants: # (new in 1.8)
+  Enabled: true
+Lint/DuplicateBranch: # (new in 1.3)
+  Enabled: true
+Lint/DuplicateRegexpCharacterClassElement: # (new in 1.1)
+  Enabled: true
+Lint/EmptyBlock: # (new in 1.1)
+  Enabled: true
+Lint/EmptyClass: # (new in 1.3)
+  Enabled: true
+Lint/EmptyInPattern: # (new in 1.16)
+  Enabled: true
+Lint/LambdaWithoutLiteralBlock: # (new in 1.8)
+  Enabled: true
+Lint/NoReturnInBeginEndBlocks: # (new in 1.2)
+  Enabled: true
+Lint/NumberedParameterAssignment: # (new in 1.9)
+  Enabled: true
+Lint/OrAssignmentToConstant: # (new in 1.9)
+  Enabled: true
+Lint/RedundantDirGlobSort: # (new in 1.8)
+  Enabled: true
+Lint/SymbolConversion: # (new in 1.9)
+  Enabled: true
+Lint/ToEnumArguments: # (new in 1.1)
+  Enabled: true
+Lint/TripleQuotes: # (new in 1.9)
+  Enabled: true
+Lint/UnexpectedBlockArity: # (new in 1.5)
+  Enabled: true
+Lint/UnmodifiedReduceAccumulator: # (new in 1.1)
+  Enabled: true
+Naming/InclusiveLanguage: # (new in 1.18)
+  Enabled: true
+Style/ArgumentsForwarding: # (new in 1.1)
+  Enabled: true
+Style/CollectionCompact: # (new in 1.2)
+  Enabled: true
+Style/DocumentDynamicEvalDefinition: # (new in 1.1)
+  Enabled: true
+Style/EndlessMethod: # (new in 1.8)
+  Enabled: true
+Style/HashConversion: # (new in 1.10)
+  Enabled: true
+Style/HashExcept: # (new in 1.7)
+  Enabled: true
+Style/IfWithBooleanLiteralBranches: # (new in 1.9)
+  Enabled: true
+Style/InPatternThen: # (new in 1.16)
+  Enabled: true
+Style/MultilineInPatternThen: # (new in 1.16)
+  Enabled: true
+Style/NegatedIfElseCondition: # (new in 1.2)
+  Enabled: true
+Style/NilLambda: # (new in 1.3)
+  Enabled: true
+Style/QuotedSymbols: # (new in 1.16)
+  Enabled: true
+Style/RedundantArgument: # (new in 1.4)
+  Enabled: true
+Style/RedundantSelfAssignmentBranch: # (new in 1.19)
+  Enabled: true
+Style/StringChars: # (new in 1.12)
+  Enabled: true
+Style/SwapValues: # (new in 1.1)
+  Enabled: true
+Performance/AncestorsInclude: # (new in 1.7)
+  Enabled: true
+Performance/BigDecimalWithNumericArgument: # (new in 1.7)
+  Enabled: true
diff --git a/.rubocop_todo.yml b/.rubocop_todo.yml
index f9b7fdd11..6f6c227de 100644
--- a/.rubocop_todo.yml
+++ b/.rubocop_todo.yml
@@ -1,32 +1,57 @@
 # This configuration was generated by
 # `rubocop --auto-gen-config`
-# on 2021-04-14 06:51:37 UTC using RuboCop version 0.90.0.
+# on 2021-08-16 15:31:43 UTC using RuboCop version 1.19.0.
 # The point is for the user to remove these configuration records
 # one by one as the offenses are removed from the code base.
 # Note that changes in the inspected code, or installation of new
 # versions of RuboCop, may require this file to be generated again.
 
-# Offense count: 26
-# Configuration parameters: IgnoredMethods.
+# Offense count: 7
+# Configuration parameters: AllowedMethods.
+# AllowedMethods: enums
+Lint/ConstantDefinitionInBlock:
+  Exclude:
+    - 'spec/faraday/composite_read_io_spec.rb'
+    - 'spec/faraday/options/options_spec.rb'
+    - 'spec/faraday/rack_builder_spec.rb'
+    - 'spec/faraday/request/instrumentation_spec.rb'
+
+# Offense count: 11
+# Configuration parameters: AllowComments, AllowEmptyLambdas.
+Lint/EmptyBlock:
+  Exclude:
+    - 'spec/faraday/connection_spec.rb'
+    - 'spec/faraday/rack_builder_spec.rb'
+    - 'spec/faraday/response_spec.rb'
+
+# Offense count: 16
+# Configuration parameters: IgnoredMethods, CountRepeatedAttributes.
 Metrics/AbcSize:
   Max: 42
 
-# Offense count: 5
+# Offense count: 3
 # Configuration parameters: CountComments, CountAsOne.
 Metrics/ClassLength:
-  Max: 256
+  Max: 226
 
-# Offense count: 15
+# Offense count: 12
 # Configuration parameters: IgnoredMethods.
 Metrics/CyclomaticComplexity:
   Max: 13
 
-# Offense count: 43
-# Configuration parameters: CountComments, CountAsOne, ExcludedMethods.
+# Offense count: 27
+# Configuration parameters: CountComments, CountAsOne, ExcludedMethods, IgnoredMethods.
 Metrics/MethodLength:
-  Max: 37
+  Max: 33
 
-# Offense count: 9
+# Offense count: 8
 # Configuration parameters: IgnoredMethods.
 Metrics/PerceivedComplexity:
   Max: 14
+
+# Offense count: 3
+Style/DocumentDynamicEvalDefinition:
+  Exclude:
+    - 'lib/faraday/connection.rb'
+    - 'lib/faraday/options.rb'
+
diff --git a/Gemfile b/Gemfile
index 1cad39848..80777df34 100644
--- a/Gemfile
+++ b/Gemfile
@@ -19,8 +19,7 @@ group :development, :test do
 end
 
 group :development, :lint do
-  gem 'rubocop', '~> 0.90.0'
-  gem 'rubocop-inclusivity', '~> 1.0'
+  gem 'rubocop'
   gem 'rubocop-packaging', '~> 0.5'
   gem 'rubocop-performance', '~> 1.0'
   gem 'yard-junk'
diff --git a/examples/client_test.rb b/examples/client_test.rb
index 148f5fccf..e4dbfe433 100644
--- a/examples/client_test.rb
+++ b/examples/client_test.rb
@@ -42,7 +42,7 @@ def test_sushi_name
     stubs.verify_stubbed_calls
   end
 
-  def test_sushi_404
+  def test_sushi_not_found
     stubs = Faraday::Adapter::Test::Stubs.new
     stubs.get('/ebi') do
       [
diff --git a/faraday.gemspec b/faraday.gemspec
index 96e0669f4..c343c2d90 100644
--- a/faraday.gemspec
+++ b/faraday.gemspec
@@ -13,7 +13,7 @@ Gem::Specification.new do |spec|
   spec.homepage = 'https://lostisland.github.io/faraday'
   spec.licenses = ['MIT']
 
-  spec.required_ruby_version = '>= 2.4'
+  spec.required_ruby_version = '>= 2.6'
 
   spec.add_dependency 'faraday-net_http', '~> 1.0'
   spec.add_dependency 'multipart-post', '>= 1.2', '< 3'
diff --git a/lib/faraday/connection.rb b/lib/faraday/connection.rb
index 1b035677b..8d8973eb1 100644
--- a/lib/faraday/connection.rb
+++ b/lib/faraday/connection.rb
@@ -469,14 +469,12 @@ def build_exclusive_url(url = nil, params = nil, params_encoder = nil)
       if url && base.path && base.path !~ %r{/$}
         base.path = "#{base.path}/" # ensure trailing slash
       end
-      url = url && URI.parse(url.to_s).opaque ? url.to_s.gsub(':', '%3A') : url
+      url = url.to_s.gsub(':', '%3A') if url && URI.parse(url.to_s).opaque
       uri = url ? base + url : base
       if params
         uri.query = params.to_query(params_encoder || options.params_encoder)
       end
-      # rubocop:disable Style/SafeNavigation
       uri.query = nil if uri.query && uri.query.empty?
-      # rubocop:enable Style/SafeNavigation
       uri
     end
 
@@ -552,7 +550,7 @@ def proxy_for_request(url)
     end
 
     def support_parallel?(adapter)
-      adapter&.respond_to?(:supports_parallel?) && adapter&.supports_parallel?
+      adapter.respond_to?(:supports_parallel?) && adapter&.supports_parallel?
     end
   end
 end
diff --git a/lib/faraday/encoders/nested_params_encoder.rb b/lib/faraday/encoders/nested_params_encoder.rb
index 705cd3e50..be5ee9b2a 100644
--- a/lib/faraday/encoders/nested_params_encoder.rb
+++ b/lib/faraday/encoders/nested_params_encoder.rb
@@ -102,7 +102,7 @@ def decode_pair(key, value, context)
       subkeys = key.scan(SUBKEYS_REGEX)
       subkeys.each_with_index do |subkey, i|
         is_array = subkey =~ /[\[\]]+\Z/
-        subkey = $` if is_array
+        subkey = Regexp.last_match.pre_match if is_array
         last_subkey = i == subkeys.length - 1
 
         context = prepare_context(context, subkey, is_array, last_subkey)
@@ -124,7 +124,7 @@ def new_context(subkey, is_array, context)
       value_type = is_array ? Array : Hash
       if context[subkey] && !context[subkey].is_a?(value_type)
         raise TypeError, "expected #{value_type.name} " \
-          "(got #{context[subkey].class.name}) for param `#{subkey}'"
+                         "(got #{context[subkey].class.name}) for param `#{subkey}'"
       end
 
       context[subkey] ||= value_type.new
diff --git a/lib/faraday/options.rb b/lib/faraday/options.rb
index ee198d8df..d6d8353a3 100644
--- a/lib/faraday/options.rb
+++ b/lib/faraday/options.rb
@@ -104,7 +104,7 @@ def empty?
 
     # Public
     def each_key(&block)
-      return to_enum(:each_key) unless block_given?
+      return to_enum(:each_key) unless block
 
       keys.each(&block)
     end
@@ -118,7 +118,7 @@ def key?(key)
 
     # Public
     def each_value(&block)
-      return to_enum(:each_value) unless block_given?
+      return to_enum(:each_value) unless block
 
       values.each(&block)
     end
@@ -168,7 +168,7 @@ def self.attribute_options
     end
 
     def self.memoized(key, &block)
-      unless block_given?
+      unless block
         raise ArgumentError, '#memoized must be called with a block'
       end
 
diff --git a/lib/faraday/rack_builder.rb b/lib/faraday/rack_builder.rb
index 42da63478..c000d51f9 100644
--- a/lib/faraday/rack_builder.rb
+++ b/lib/faraday/rack_builder.rb
@@ -61,7 +61,7 @@ def build(app = nil)
     def initialize(handlers = [], adapter = nil, &block)
       @adapter = adapter
       @handlers = handlers
-      if block_given?
+      if block
         build(&block)
       elsif @handlers.empty?
         # default stack, if nothing else is configured
diff --git a/lib/faraday/response.rb b/lib/faraday/response.rb
index 187525a4b..505e4ea43 100644
--- a/lib/faraday/response.rb
+++ b/lib/faraday/response.rb
@@ -38,10 +38,10 @@ def finished?
     end
 
     def on_complete(&block)
-      if !finished?
-        @on_complete_callbacks << block
-      else
+      if finished?
         yield(env)
+      else
+        @on_complete_callbacks << block
       end
       self
     end
diff --git a/lib/faraday/utils/headers.rb b/lib/faraday/utils/headers.rb
index 9883dc24c..8e8755216 100644
--- a/lib/faraday/utils/headers.rb
+++ b/lib/faraday/utils/headers.rb
@@ -111,7 +111,7 @@ def to_hash
       def parse(header_string)
         return unless header_string && !header_string.empty?
 
-        headers = header_string.split(/\r\n/)
+        headers = header_string.split("\r\n")
 
         # Find the last set of response headers.
         start_index = headers.rindex { |x| x.start_with?('HTTP/') } || 0
diff --git a/spec/faraday/options/env_spec.rb b/spec/faraday/options/env_spec.rb
index 04a4b5e88..194cbdc6b 100644
--- a/spec/faraday/options/env_spec.rb
+++ b/spec/faraday/options/env_spec.rb
@@ -29,12 +29,12 @@
 
   it 'retains custom members' do
     env[:foo] = 'custom 1'
-    env[:bar] = :custom_2
+    env[:bar] = :custom2
     env2 = Faraday::Env.from(env)
     env2[:baz] = 'custom 3'
 
     expect(env2[:foo]).to eq('custom 1')
-    expect(env2[:bar]).to eq(:custom_2)
+    expect(env2[:bar]).to eq(:custom2)
     expect(env[:baz]).to be_nil
   end
 
diff --git a/spec/faraday/rack_builder_spec.rb b/spec/faraday/rack_builder_spec.rb
index e00691673..b9a4ef957 100644
--- a/spec/faraday/rack_builder_spec.rb
+++ b/spec/faraday/rack_builder_spec.rb
@@ -12,8 +12,10 @@ def call(env)
 
   class Apple < Handler
   end
+
   class Orange < Handler
   end
+
   class Banana < Handler
   end
 
diff --git a/spec/faraday/request/instrumentation_spec.rb b/spec/faraday/request/instrumentation_spec.rb
index f8af4c4f5..d207c5568 100644
--- a/spec/faraday/request/instrumentation_spec.rb
+++ b/spec/faraday/request/instrumentation_spec.rb
@@ -30,13 +30,11 @@ def instrument(name, env)
 
   it { expect(options.name).to eq('request.faraday') }
   it 'defaults to ActiveSupport::Notifications' do
-    begin
-      res = options.instrumenter
-    rescue NameError => e
-      expect(e.to_s).to match('ActiveSupport')
-    else
-      expect(res).to eq(ActiveSupport::Notifications)
-    end
+    res = options.instrumenter
+  rescue NameError => e
+    expect(e.to_s).to match('ActiveSupport')
+  else
+    expect(res).to eq(ActiveSupport::Notifications)
   end
 
   it 'instruments with default name' do
diff --git a/spec/faraday/response/json_spec.rb b/spec/faraday/response/json_spec.rb
index a98e8a586..884746e20 100644
--- a/spec/faraday/response/json_spec.rb
+++ b/spec/faraday/response/json_spec.rb
@@ -76,12 +76,10 @@ def process(body, content_type = 'application/json', options = {})
   end
 
   it 'includes the response on the ParsingError instance' do
-    begin
-      process('{') { |env| env[:response] = Faraday::Response.new }
-      raise 'Parsing should have failed.'
-    rescue Faraday::ParsingError => e
-      expect(e.response).to be_a(Faraday::Response)
-    end
+    process('{') { |env| env[:response] = Faraday::Response.new }
+    raise 'Parsing should have failed.'
+  rescue Faraday::ParsingError => e
+    expect(e.response).to be_a(Faraday::Response)
   end
 
   context 'HEAD responses' do
diff --git a/spec/faraday/utils_spec.rb b/spec/faraday/utils_spec.rb
index c3da7462c..8bcf3f186 100644
--- a/spec/faraday/utils_spec.rb
+++ b/spec/faraday/utils_spec.rb
@@ -4,7 +4,7 @@
   describe 'headers parsing' do
     let(:multi_response_headers) do
       "HTTP/1.x 500 OK\r\nContent-Type: text/html; charset=UTF-8\r\n" \
-      "HTTP/1.x 200 OK\r\nContent-Type: application/json; charset=UTF-8\r\n\r\n"
+        "HTTP/1.x 200 OK\r\nContent-Type: application/json; charset=UTF-8\r\n\r\n"
     end
 
     it 'parse headers for aggregated responses' do
diff --git a/spec/support/fake_safe_buffer.rb b/spec/support/fake_safe_buffer.rb
index 62a56aa58..69afd6ea9 100644
--- a/spec/support/fake_safe_buffer.rb
+++ b/spec/support/fake_safe_buffer.rb
@@ -8,7 +8,7 @@ def to_s
 
   def gsub(regex)
     string.gsub(regex) do
-      match, = $&, '' =~ /a/
+      match, = Regexp.last_match(0), '' =~ /a/ # rubocop:disable Performance/StringInclude
       yield(match)
     end
   end
diff --git a/spec/support/shared_examples/request_method.rb b/spec/support/shared_examples/request_method.rb
index cb7125106..6d974f9fc 100644
--- a/spec/support/shared_examples/request_method.rb
+++ b/spec/support/shared_examples/request_method.rb
@@ -79,7 +79,7 @@
 
   on_feature :request_body_on_query_methods do
     it 'sends request body' do
-      request_stub.with(Hash[:body, 'test'])
+      request_stub.with({ body: 'test' })
       res = if query_or_body == :body
               conn.public_send(http_method, '/', 'test')
             else
@@ -93,7 +93,7 @@
 
   it 'sends url encoded parameters' do
     payload = { name: 'zack' }
-    request_stub.with(Hash[query_or_body, payload])
+    request_stub.with({ query_or_body => payload })
     res = conn.public_send(http_method, '/', payload)
     if query_or_body == :query
       expect(res.env.request_body).to be_nil
@@ -104,7 +104,7 @@
 
   it 'sends url encoded nested parameters' do
     payload = { name: { first: 'zack' } }
-    request_stub.with(Hash[query_or_body, payload])
+    request_stub.with({ query_or_body => payload })
     conn.public_send(http_method, '/', payload)
   end
 
@@ -199,11 +199,11 @@
         @payload2 = { b: '2' }
 
         request_stub
-          .with(Hash[query_or_body, @payload1])
+          .with({ query_or_body => @payload1 })
           .to_return(body: @payload1.to_json)
 
         stub_request(http_method, remote)
-          .with(Hash[query_or_body, @payload2])
+          .with({ query_or_body => @payload2 })
           .to_return(body: @payload2.to_json)
 
         conn.in_parallel do