diff --git a/.github/workflows/lint-app.yml b/.github/workflows/lint-app.yml
deleted file mode 100644
index 99b48ce..0000000
--- a/.github/workflows/lint-app.yml
+++ /dev/null
@@ -1,17 +0,0 @@
-name: Rubocop checking
-
-on: [push]
-
-jobs:
-  lint:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/checkout@v4
-    - name: Set up Ruby
-      uses: ruby/setup-ruby@v1
-      with:
-        ruby-version: 2.7
-    - name: Install dependencies (bundle)
-      run: bundle install
-    - name: Run Rubocop
-      run: bundle exec rubocop
diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 5501c93..37a9997 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -9,7 +9,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout code
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
         with:
           fetch-depth: 0
 
diff --git a/.github/workflows/test-app.yml b/.github/workflows/test-app.yml
index c89b792..49c8e0d 100644
--- a/.github/workflows/test-app.yml
+++ b/.github/workflows/test-app.yml
@@ -1,19 +1,26 @@
 name: Ruby tests
 
-on: [push, pull_request]
+on: pull_request
 
 jobs:
   test:
     strategy:
       matrix:
-        ruby: ['2.7', '3.0', '3.1', '3.2', '3.3']
+        # In support versions of Ruby this Gem will be tested against.
+        # This should correspond to the version range in the gemfile.
+        ruby: ['3.3', '3.4']
     runs-on: ubuntu-latest
     steps:
-    - uses: actions/checkout@v4
+    - uses: actions/checkout@v6
     - name: Set up Ruby
-      uses: ruby/setup-ruby@v1
+      uses: ruby/setup-ruby@v1.316.0
       with:
         ruby-version: ${{ matrix.ruby }}
         bundler-cache: true
+    - name: Run Rubocop
+      # Note that Rubocop will conservatively use the minimal version from the gemfile for its rules
+      # we should only run it on the minimal Ruby version
+      if: matrix.ruby == '3.3'
+      run: bundle exec rubocop
     - name: Run tests
       run: bundle exec rake test
diff --git a/.rubocop.yml b/.rubocop.yml
index 2ada576..8330b68 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -1,5 +1,4 @@
 AllCops:
-  TargetRubyVersion: 2.7
   NewCops: enable
 Style/FrozenStringLiteralComment:
   Enabled: true
diff --git a/.ruby-version b/.ruby-version
deleted file mode 100644
index 6a81b4c..0000000
--- a/.ruby-version
+++ /dev/null
@@ -1 +0,0 @@
-2.7.8
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 012cbb5..13ad8f4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,11 @@
 
 All notable changes will be documented in this file.
 
+## Unreleased
+
+- (Bogdan) Moved development dependencies from `gemspec` to `Gemfile` and updated
+  all dependencies [#37](https://github.com/epimorphics/nrw-landing/issues/37)
+
 ## 1.4.0 - 2026-03-04
 
 - (AlexT) When finding wrapper type, select the most specific type if more are available
diff --git a/Gemfile b/Gemfile
index c868835..bd332c2 100644
--- a/Gemfile
+++ b/Gemfile
@@ -6,3 +6,15 @@ source 'https://rubygems.org'
 
 # Specify your gem's dependencies in sapi-nt-client-ruby.gemspec
 gemspec
+
+group :development do
+  gem 'bundler'
+  gem 'byebug'
+  gem 'minitest', '~> 5.0'
+  gem 'minitest-reporters', '~> 1.0'
+  gem 'mocha', '~> 2.0'
+  gem 'rake'
+  gem 'rubocop'
+  gem 'simplecov'
+  gem 'vcr', '~> 6.0'
+end
diff --git a/Gemfile.lock b/Gemfile.lock
index b4c138e..707123d 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -9,12 +9,12 @@ GEM
   remote: https://rubygems.org/
   specs:
     ansi (1.5.0)
-    ast (2.4.2)
+    ast (2.4.3)
     builder (3.3.0)
     byebug (11.1.3)
-    concurrent-ruby (1.3.4)
+    concurrent-ruby (1.3.7)
     docile (1.4.1)
-    faraday (1.10.4)
+    faraday (1.10.6)
       faraday-em_http (~> 1.0)
       faraday-em_synchrony (~> 1.0)
       faraday-excon (~> 1.1)
@@ -27,74 +27,83 @@ GEM
       faraday-retry (~> 1.0)
       ruby2_keywords (>= 0.0.4)
     faraday-em_http (1.0.0)
-    faraday-em_synchrony (1.0.0)
+    faraday-em_synchrony (1.0.1)
     faraday-excon (1.1.0)
     faraday-httpclient (1.0.1)
-    faraday-multipart (1.1.0)
+    faraday-multipart (1.2.0)
       multipart-post (~> 2.0)
     faraday-net_http (1.0.2)
     faraday-net_http_persistent (1.2.0)
     faraday-patron (1.0.0)
     faraday-rack (1.0.0)
-    faraday-retry (1.0.3)
+    faraday-retry (1.0.4)
     faraday_middleware (1.0.0)
       faraday (~> 1.0)
-    i18n (1.14.6)
+    i18n (1.14.8)
       concurrent-ruby (~> 1.0)
-    minitest (5.25.4)
-    minitest-reporters (1.7.1)
+    json (2.20.0)
+    language_server-protocol (3.17.0.6)
+    lint_roller (1.1.0)
+    minitest (5.26.1)
+    minitest-reporters (1.8.0)
       ansi
       builder
-      minitest (>= 5.0)
+      minitest (>= 5.0, < 7)
       ruby-progressbar
-    mocha (2.7.1)
+    mocha (2.8.2)
       ruby2_keywords (>= 0.0.5)
     multipart-post (2.4.1)
-    parallel (1.26.3)
-    parser (3.3.6.0)
+    parallel (1.28.0)
+    parser (3.3.11.1)
       ast (~> 2.4.1)
       racc
+    prism (1.9.0)
     racc (1.8.1)
     rainbow (3.1.1)
-    rake (13.0.6)
-    regexp_parser (2.10.0)
-    rexml (3.4.0)
-    rubocop (1.26.1)
-      parallel (~> 1.10)
-      parser (>= 3.1.0.0)
+    rake (13.4.2)
+    regexp_parser (2.12.0)
+    rubocop (1.88.2)
+      json (~> 2.3)
+      language_server-protocol (~> 3.17.0.2)
+      lint_roller (~> 1.1.0)
+      parallel (>= 1.10)
+      parser (>= 3.3.0.2)
       rainbow (>= 2.2.2, < 4.0)
-      regexp_parser (>= 1.8, < 3.0)
-      rexml
-      rubocop-ast (>= 1.16.0, < 2.0)
+      regexp_parser (>= 2.9.3, < 3.0)
+      rubocop-ast (>= 1.49.0, < 2.0)
       ruby-progressbar (~> 1.7)
-      unicode-display_width (>= 1.4.0, < 3.0)
-    rubocop-ast (1.37.0)
-      parser (>= 3.3.1.0)
+      unicode-display_width (>= 2.4.0, < 4.0)
+    rubocop-ast (1.50.0)
+      parser (>= 3.3.7.2)
+      prism (~> 1.7)
     ruby-progressbar (1.13.0)
     ruby2_keywords (0.0.5)
-    simplecov (0.21.2)
+    simplecov (0.22.0)
       docile (~> 1.1)
       simplecov-html (~> 0.11)
       simplecov_json_formatter (~> 0.1)
-    simplecov-html (0.13.1)
+    simplecov-html (0.13.2)
     simplecov_json_formatter (0.1.4)
-    unicode-display_width (2.6.0)
-    vcr (6.0.0)
+    unicode-display_width (3.2.0)
+      unicode-emoji (~> 4.1)
+    unicode-emoji (4.2.0)
+    vcr (6.4.0)
 
 PLATFORMS
-  ruby
+  x86_64-darwin-24
+  x86_64-linux
 
 DEPENDENCIES
-  bundler (~> 2.4.22)
-  byebug (~> 11.1.3)
-  minitest (~> 5.25)
-  minitest-reporters (~> 1.7)
-  mocha (~> 2.4)
-  rake (~> 13.0.1)
-  rubocop (~> 1.26.0)
+  bundler
+  byebug
+  minitest (~> 5.0)
+  minitest-reporters (~> 1.0)
+  mocha (~> 2.0)
+  rake
+  rubocop
   sapi-client-ruby!
-  simplecov (~> 0.21.1)
-  vcr (~> 6.0.0)
+  simplecov
+  vcr (~> 6.0)
 
 BUNDLED WITH
    2.4.22
diff --git a/exe/sapi b/exe/sapi
index e6fc03e..e2358b6 100755
--- a/exe/sapi
+++ b/exe/sapi
@@ -1,13 +1,13 @@
 #!/usr/bin/env ruby
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 require 'bundler/setup'
 require 'optparse'
 require 'sapi_client'
 
 options = {
-  base: ENV['SAPI_BASE_URL'],
-  spec: ENV['SAPI_SPEC_FILE'] || ENV['SAPI_SPEC']
+  base: ENV.fetch('SAPI_BASE_URL', nil),
+  spec: ENV['SAPI_SPEC_FILE'] || ENV.fetch('SAPI_SPEC', nil)
 }
 
 def spec_file_or_dir(options)
diff --git a/lib/sapi_client/application.rb b/lib/sapi_client/application.rb
index f9b62f1..38346a0 100644
--- a/lib/sapi_client/application.rb
+++ b/lib/sapi_client/application.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Wraps an entire Sapi-NT application, such that we can walk over all of the
diff --git a/lib/sapi_client/endpoint_group.rb b/lib/sapi_client/endpoint_group.rb
index 958f20a..0bb40b4 100644
--- a/lib/sapi_client/endpoint_group.rb
+++ b/lib/sapi_client/endpoint_group.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Encapsulates the specification of a group of SAPI endpoints, and some
diff --git a/lib/sapi_client/endpoint_values.rb b/lib/sapi_client/endpoint_values.rb
index 253df01..04d4c7a 100644
--- a/lib/sapi_client/endpoint_values.rb
+++ b/lib/sapi_client/endpoint_values.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Encapsulates a set of values from a given endpoint, conditioned by various
diff --git a/lib/sapi_client/hierarchy_resource.rb b/lib/sapi_client/hierarchy_resource.rb
index 8d1cf74..5677e49 100644
--- a/lib/sapi_client/hierarchy_resource.rb
+++ b/lib/sapi_client/hierarchy_resource.rb
@@ -8,7 +8,7 @@ class HierarchyResource < SapiResource
     attr_reader :children, :parent
 
     def initialize(resource)
-      super(resource)
+      super
       @children = []
     end
 
@@ -22,8 +22,8 @@ def add_child(resource, add_reciprocal: true)
       resource.send(:parent=, self, add_reciprocal: false) if add_reciprocal
     end
 
-    def each_child(&block)
-      children.each(&block)
+    def each_child(&)
+      children.each(&)
     end
   end
 end
diff --git a/lib/sapi_client/instance.rb b/lib/sapi_client/instance.rb
index 4683b49..88f11c8 100644
--- a/lib/sapi_client/instance.rb
+++ b/lib/sapi_client/instance.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Denotes a particular instance of a Sapi-NT API. The instance has the basic
diff --git a/lib/sapi_client/resource_wrapper.rb b/lib/sapi_client/resource_wrapper.rb
index 45363fa..3a19414 100644
--- a/lib/sapi_client/resource_wrapper.rb
+++ b/lib/sapi_client/resource_wrapper.rb
@@ -30,11 +30,11 @@ def self.default_resource_wrapper_type
     # Find the first wrapper type for which there is an existing
     # class constant with the same name. If no such value is
     # found, return the default resource wrapper
-    # rubocop:disable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength
+    # rubocop:disable Metrics/MethodLength
     def self.find_wrapper_type(types)
       all_wrapped = Array(types)
                     .map { |type| wrapper_class_constant(de_uri(type)) }
-                    .filter { |wrapper| !wrapper.nil? }
+                    .compact
       most_specific_wrapped = all_wrapped
                               .filter do |t|
         all_wrapped.none? do |a|
@@ -45,7 +45,7 @@ def self.find_wrapper_type(types)
 
       default_resource_wrapper_type
     end
-    # rubocop:enable Metrics/AbcSize, Metrics/CyclomaticComplexity, Metrics/MethodLength
+    # rubocop:enable Metrics/MethodLength
 
     # Return the wrapper class for the given resource. If the
     # `options` specifies the wrapper class, then use that.
diff --git a/lib/sapi_client/sapi_endpoint.rb b/lib/sapi_client/sapi_endpoint.rb
index 7d83bd3..6a5cf03 100644
--- a/lib/sapi_client/sapi_endpoint.rb
+++ b/lib/sapi_client/sapi_endpoint.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Denotes a single SAPI-NT endpoint, which we can call to get back JSON data
diff --git a/lib/sapi_client/sapi_resource.rb b/lib/sapi_client/sapi_resource.rb
index 80ac44e..8198f64 100644
--- a/lib/sapi_client/sapi_resource.rb
+++ b/lib/sapi_client/sapi_resource.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Encapsulates a JSON-LD -style resource that we get back from a Sapi-NT endpoint,
@@ -193,7 +193,7 @@ def lang_select(values, preferred_lang)
     # Return the given value as an un-wrapped resource. A Hash given to this
     # method will have its keys transformed to symbols.
     def as_resource(res)
-      if res.is_a?(SapiResource) # rubocop:disable Style/CaseLikeIf
+      if res.is_a?(SapiResource)
         res.resource.clone
       elsif res.is_a?(Hash)
         hash_with_symbol_keys(res)
diff --git a/lib/sapi_client/version.rb b/lib/sapi_client/version.rb
index 88ff5e8..962942a 100644
--- a/lib/sapi_client/version.rb
+++ b/lib/sapi_client/version.rb
@@ -4,5 +4,5 @@ module SapiClient
   MAJOR = 1
   MINOR = 4
   FIX = 0
-  VERSION = "#{MAJOR}.#{MINOR}.#{FIX}"
+  VERSION = "#{MAJOR}.#{MINOR}.#{FIX}".freeze
 end
diff --git a/lib/sapi_client/view.rb b/lib/sapi_client/view.rb
index a8601a1..ae9f628 100644
--- a/lib/sapi_client/view.rb
+++ b/lib/sapi_client/view.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 module SapiClient
   # Encapsulates a view of a Sapi-NT endpoint, which tells us information about
diff --git a/sapi-client-ruby.gemspec b/sapi-client-ruby.gemspec
index 449e96b..bbede1f 100644
--- a/sapi-client-ruby.gemspec
+++ b/sapi-client-ruby.gemspec
@@ -5,7 +5,7 @@ $LOAD_PATH.unshift(lib) unless $LOAD_PATH.include?(lib)
 require 'sapi_client/version'
 
 Gem::Specification.new do |spec|
-  spec.required_ruby_version = '>= 2.7.8'
+  spec.required_ruby_version = '~> 3.3'
   spec.name          = 'sapi-client-ruby'
   spec.version       = SapiClient::VERSION
   spec.authors       = ['Epimorphics Ltd']
@@ -33,14 +33,4 @@ Gem::Specification.new do |spec|
 
   spec.add_dependency 'faraday_middleware', '~> 1.0.0'
   spec.add_dependency 'i18n', '~> 1.5'
-
-  spec.add_development_dependency 'bundler', '~> 2.4.22'
-  spec.add_development_dependency 'byebug', '~> 11.1.3'
-  spec.add_development_dependency 'minitest', '~> 5.25'
-  spec.add_development_dependency 'minitest-reporters', '~> 1.7'
-  spec.add_development_dependency 'mocha', '~> 2.4'
-  spec.add_development_dependency 'rake', '~> 13.0.1'
-  spec.add_development_dependency 'rubocop', '~> 1.26.0'
-  spec.add_development_dependency 'simplecov', '~> 0.21.1'
-  spec.add_development_dependency 'vcr', '~> 6.0.0'
 end
diff --git a/test/sapi_client/endpoint_values_test.rb b/test/sapi_client/endpoint_values_test.rb
index 5ae5a31..5ed98e6 100644
--- a/test/sapi_client/endpoint_values_test.rb
+++ b/test/sapi_client/endpoint_values_test.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 require 'test_helper'
 require 'sapi_client'
diff --git a/test/sapi_client/sapi_resource_test.rb b/test/sapi_client/sapi_resource_test.rb
index 9df921d..1c6bb93 100644
--- a/test/sapi_client/sapi_resource_test.rb
+++ b/test/sapi_client/sapi_resource_test.rb
@@ -1,4 +1,4 @@
-# frozen-string-literal: true
+# frozen_string_literal: true
 
 require 'test_helper'
 require 'sapi_client'