diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1ab808e..7066d5f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -20,7 +20,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        ruby-version: ['3.4']
+        ruby-version: ['4.0']
         node-version: ['18']
         puppeteer-version: [
           '22.15.0',
@@ -40,6 +40,9 @@ jobs:
           - ruby-version: '3.3'
             node-version: '18'
             puppeteer-version: '24.10.2'
+          - ruby-version: '3.4'
+            node-version: '18'
+            puppeteer-version: '24.10.2'
           - ruby-version: '3.4'
             node-version: '20'
             puppeteer-version: '24.10.2'
@@ -49,7 +52,13 @@ jobs:
           - ruby-version: '3.4'
             node-version: '24'
             puppeteer-version: '24.10.2'
-          - ruby-version: '3.5.0-preview1'
+          - ruby-version: '4.0'
+            node-version: '20'
+            puppeteer-version: '24.10.2'
+          - ruby-version: '4.0'
+            node-version: '22'
+            puppeteer-version: '24.10.2'
+          - ruby-version: '4.0'
             node-version: '24'
             puppeteer-version: '24.10.2'
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index dde41a3..50af07a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,7 +1,8 @@
 # Changelog
 
 ## Unreleased
-- none
+### Added
+- Add support for Ruby 4.0
 
 ## [1.2,4](releases/tag/v1.2.4) - 2025-11-04
 ### Added
diff --git a/grover.gemspec b/grover.gemspec
index 6832c7f..252cd94 100644
--- a/grover.gemspec
+++ b/grover.gemspec
@@ -16,7 +16,7 @@ Gem::Specification.new do |spec|
   SUMMARY
   spec.homepage    = 'https://github.com/Studiosity/grover'
   spec.license     = 'MIT'
-  spec.required_ruby_version = ['>= 3.0.0', '< 3.5.0']
+  spec.required_ruby_version = ['>= 3.0.0', '< 4.1.0']
 
   # Prevent pushing this gem to RubyGems.org by setting 'allowed_push_host', or
   # delete this section to allow pushing this gem to any host.
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 044eea2..eedfc30 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -37,11 +37,11 @@ def fixture_path(file)
 end
 
 def puppeteer_version_on_or_after?(version)
-  puppeteer_version.empty? || Gem::Version.new(puppeteer_version) >= Gem::Version.new(version)
+  puppeteer_version.nil? || puppeteer_version.empty? || Gem::Version.new(puppeteer_version) >= Gem::Version.new(version)
 end
 
 def puppeteer_version_on_or_before?(version)
-  puppeteer_version.empty? || Gem::Version.new(puppeteer_version) <= Gem::Version.new(version)
+  puppeteer_version.nil? || puppeteer_version.empty? || Gem::Version.new(puppeteer_version) <= Gem::Version.new(version)
 end
 
 def puppeteer_version