diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index c060c93..cd5b98d 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -12,15 +12,13 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-        - '3.0'
-        - '2.7'
-        - '2.6'
-        - '2.5'
+        - '3.3'
+        - '3.2'
 
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: "${{matrix.ruby}}"
     - name: Install dependencies and run RSpec
@@ -35,15 +33,13 @@ jobs:
       fail-fast: false
       matrix:
         ruby:
-        - '3.0'
-        - '2.7'
-        - '2.6'
-        - '2.5'
+        - '3.3'
+        - '3.2'
 
     steps:
     - uses: actions/checkout@v2
     - name: Set up Ruby
-      uses: actions/setup-ruby@v1
+      uses: ruby/setup-ruby@v1
       with:
         ruby-version: "${{matrix.ruby}}"
     - name: Install dependencies and run rubocop"
diff --git a/.gitignore b/.gitignore
index b04a8c8..a4be4c3 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 /pkg/
 /spec/reports/
 /tmp/
+Gemfile.lock
 
 # rspec failure tracking
 .rspec_status
diff --git a/Gemfile b/Gemfile
index d13ebdf..279ea71 100644
--- a/Gemfile
+++ b/Gemfile
@@ -5,4 +5,19 @@ source "https://rubygems.org"
 # Specify your gem's dependencies in rubytoolbox-api.gemspec
 gemspec
 
+gem "rubocop"
+gem "rubocop-performance"
+gem "rubocop-rake"
+gem "rubocop-rspec"
+
+gem "guard-bundler"
+gem "guard-rspec"
+gem "guard-rubocop"
+
+gem "rspec", ">= 3.9"
+gem "simplecov", ">= 0.18.5"
+
+gem "vcr", ">= 5.1.0"
+gem "webmock", ">= 3.8.3"
+
 gem "rake", "~> 12.0"
diff --git a/Gemfile.lock b/Gemfile.lock
deleted file mode 100644
index 0f8f792..0000000
--- a/Gemfile.lock
+++ /dev/null
@@ -1,130 +0,0 @@
-PATH
-  remote: .
-  specs:
-    rubytoolbox-api (0.2.0)
-
-GEM
-  remote: https://rubygems.org/
-  specs:
-    addressable (2.8.0)
-      public_suffix (>= 2.0.2, < 5.0)
-    ast (2.4.2)
-    coderay (1.1.3)
-    crack (0.4.5)
-      rexml
-    diff-lcs (1.4.4)
-    docile (1.4.0)
-    ffi (1.15.3)
-    formatador (0.3.0)
-    guard (2.18.0)
-      formatador (>= 0.2.4)
-      listen (>= 2.7, < 4.0)
-      lumberjack (>= 1.0.12, < 2.0)
-      nenv (~> 0.1)
-      notiffany (~> 0.0)
-      pry (>= 0.13.0)
-      shellany (~> 0.0)
-      thor (>= 0.18.1)
-    guard-bundler (3.0.0)
-      bundler (>= 2.1, < 3)
-      guard (~> 2.2)
-      guard-compat (~> 1.1)
-    guard-compat (1.2.1)
-    guard-rspec (4.7.3)
-      guard (~> 2.1)
-      guard-compat (~> 1.1)
-      rspec (>= 2.99.0, < 4.0)
-    guard-rubocop (1.5.0)
-      guard (~> 2.0)
-      rubocop (< 2.0)
-    hashdiff (1.0.1)
-    listen (3.7.0)
-      rb-fsevent (~> 0.10, >= 0.10.3)
-      rb-inotify (~> 0.9, >= 0.9.10)
-    lumberjack (1.2.8)
-    method_source (1.0.0)
-    nenv (0.3.0)
-    notiffany (0.1.3)
-      nenv (~> 0.1)
-      shellany (~> 0.0)
-    parallel (1.21.0)
-    parser (3.0.2.0)
-      ast (~> 2.4.1)
-    pry (0.14.1)
-      coderay (~> 1.1)
-      method_source (~> 1.0)
-    public_suffix (4.0.6)
-    rainbow (3.0.0)
-    rake (12.3.3)
-    rb-fsevent (0.11.0)
-    rb-inotify (0.10.1)
-      ffi (~> 1.0)
-    regexp_parser (2.1.1)
-    rexml (3.2.5)
-    rspec (3.10.0)
-      rspec-core (~> 3.10.0)
-      rspec-expectations (~> 3.10.0)
-      rspec-mocks (~> 3.10.0)
-    rspec-core (3.10.1)
-      rspec-support (~> 3.10.0)
-    rspec-expectations (3.10.1)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.10.0)
-    rspec-mocks (3.10.2)
-      diff-lcs (>= 1.2.0, < 2.0)
-      rspec-support (~> 3.10.0)
-    rspec-support (3.10.2)
-    rubocop (1.21.0)
-      parallel (~> 1.10)
-      parser (>= 3.0.0.0)
-      rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml
-      rubocop-ast (>= 1.9.1, < 2.0)
-      ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.11.0)
-      parser (>= 3.0.1.1)
-    rubocop-performance (1.11.5)
-      rubocop (>= 1.7.0, < 2.0)
-      rubocop-ast (>= 0.4.0)
-    rubocop-rake (0.6.0)
-      rubocop (~> 1.0)
-    rubocop-rspec (2.5.0)
-      rubocop (~> 1.19)
-    ruby-progressbar (1.11.0)
-    shellany (0.0.1)
-    simplecov (0.21.2)
-      docile (~> 1.1)
-      simplecov-html (~> 0.11)
-      simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.12.3)
-    simplecov_json_formatter (0.1.3)
-    thor (1.1.0)
-    unicode-display_width (2.1.0)
-    vcr (6.0.0)
-    webmock (3.14.0)
-      addressable (>= 2.8.0)
-      crack (>= 0.3.2)
-      hashdiff (>= 0.4.0, < 2.0.0)
-
-PLATFORMS
-  ruby
-
-DEPENDENCIES
-  guard-bundler
-  guard-rspec
-  guard-rubocop
-  rake (~> 12.0)
-  rspec (>= 3.9)
-  rubocop
-  rubocop-performance
-  rubocop-rake
-  rubocop-rspec
-  rubytoolbox-api!
-  simplecov (>= 0.18.5)
-  vcr (>= 5.1.0)
-  webmock (>= 3.8.3)
-
-BUNDLED WITH
-   2.2.25
diff --git a/lib/rubytoolbox/api/response_wrapper.rb b/lib/rubytoolbox/api/response_wrapper.rb
index d8b8cbb..67ab115 100644
--- a/lib/rubytoolbox/api/response_wrapper.rb
+++ b/lib/rubytoolbox/api/response_wrapper.rb
@@ -23,12 +23,12 @@ def field(name, &block)
 
           block ||= ->(value) { value }
 
-          define_method "#{name}=" do |value|
-            instance_variable_set "@#{name}", block.call(value)
+          define_method :"#{name}=" do |value|
+            instance_variable_set :"@#{name}", block.call(value)
           end
 
           attr_reader name
-          private "#{name}="
+          private :"#{name}="
         end
 
         def fields
@@ -40,7 +40,7 @@ def initialize(data)
         self.class.fields.each do |name|
           value = data.key?(name.to_s) ? data[name.to_s] : data[name.to_sym]
 
-          send "#{name}=", value unless value.nil?
+          send :"#{name}=", value unless value.nil?
         end
       end
 
diff --git a/rubytoolbox-api.gemspec b/rubytoolbox-api.gemspec
index 07fee75..7049bf7 100644
--- a/rubytoolbox-api.gemspec
+++ b/rubytoolbox-api.gemspec
@@ -2,7 +2,6 @@
 
 require_relative "lib/rubytoolbox/api/version"
 
-# rubocop:disable Metrics/BlockLength
 Gem::Specification.new do |spec|
   spec.name          = "rubytoolbox-api"
   spec.version       = Rubytoolbox::Api::VERSION
@@ -27,19 +26,5 @@ Gem::Specification.new do |spec|
   spec.executables   = spec.files.grep(%r{^exe/}) { |f| File.basename(f) }
   spec.require_paths = ["lib"]
 
-  spec.add_development_dependency "rubocop"
-  spec.add_development_dependency "rubocop-performance"
-  spec.add_development_dependency "rubocop-rake"
-  spec.add_development_dependency "rubocop-rspec"
-
-  spec.add_development_dependency "guard-bundler"
-  spec.add_development_dependency "guard-rspec"
-  spec.add_development_dependency "guard-rubocop"
-
-  spec.add_development_dependency "rspec", ">= 3.9"
-  spec.add_development_dependency "simplecov", ">= 0.18.5"
-
-  spec.add_development_dependency "vcr", ">= 5.1.0"
-  spec.add_development_dependency "webmock", ">= 3.8.3"
+  spec.metadata["rubygems_mfa_required"] = "true"
 end
-# rubocop:enable Metrics/BlockLength
diff --git a/spec/rubytoolbox/api/response_wrapper_spec.rb b/spec/rubytoolbox/api/response_wrapper_spec.rb
index 6a01b25..375d637 100644
--- a/spec/rubytoolbox/api/response_wrapper_spec.rb
+++ b/spec/rubytoolbox/api/response_wrapper_spec.rb
@@ -30,7 +30,7 @@
   end
 
   it "correctly handles false value when given as string key" do
-    expect(sample.new("foo" => false, bar: "123").foo).to be == false
+    expect(sample.new("foo" => false, bar: "123").foo).to be false
   end
 
   it "can be converted back to a hash" do # rubocop:disable RSpec/ExampleLength
@@ -41,7 +41,7 @@
       subcollection: [{ key: "value" }]
     )
 
-    expect(object.to_h).to be == {
+    expect(object.to_h).to eq(
       "foo" => "foo",
       "bar" => "rab",
       "sub" => {
@@ -49,7 +49,7 @@
       },
       "subcollection" => [
         { "key" => "value" },
-      ],
-    }
+      ]
+    )
   end
 end
diff --git a/spec/rubytoolbox/api_spec.rb b/spec/rubytoolbox/api_spec.rb
index 0d88ee1..7d3c1fa 100644
--- a/spec/rubytoolbox/api_spec.rb
+++ b/spec/rubytoolbox/api_spec.rb
@@ -4,16 +4,16 @@
   let(:client) { described_class.new }
 
   it "has a version number" do
-    expect(Rubytoolbox::Api::VERSION).not_to be nil
+    expect(Rubytoolbox::Api::VERSION).not_to be_nil
   end
 
   describe "initializer" do
     it "defaults endpoint_url to https://www.ruby-toolbox.com/api/" do
-      expect(described_class.new.endpoint_url).to be == "https://www.ruby-toolbox.com/api/"
+      expect(described_class.new.endpoint_url).to eq "https://www.ruby-toolbox.com/api/"
     end
 
     it "accepts a custom endpoint_url" do
-      expect(described_class.new(url: "http://localhost:5000/api/").endpoint_url).to be == "http://localhost:5000/api/"
+      expect(described_class.new(url: "http://localhost:5000/api/").endpoint_url).to eq "http://localhost:5000/api/"
     end
   end