diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 42f3e975..85b9881e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -19,9 +19,12 @@ jobs:
       matrix:
         ruby_version:
           - "3.2"
+          - "4.0"
         include:
           - ruby_version: '3.2'
             puppet_gem_version: '~> 8.0'
+          - ruby_version: '4.0'
+            puppet_gem_version: '~> 9.0'
         runs_on:
           - "ubuntu-latest"
           - "windows-latest"
@@ -40,9 +43,12 @@ jobs:
       matrix:
         ruby_version:
           - "3.2"
+          - "4.0"
         include:
           - ruby_version: '3.2'
             puppet_gem_version: 'https://github.com/puppetlabs/puppet' # puppet8'
+          - ruby_version: '4.0'
+            puppet_gem_version: '~> 9.0'
         runs_on:
           - "ubuntu-latest"
           - "windows-latest"
diff --git a/.github/workflows/nightly.yml b/.github/workflows/nightly.yml
index 304e9722..63aee7f1 100644
--- a/.github/workflows/nightly.yml
+++ b/.github/workflows/nightly.yml
@@ -12,9 +12,12 @@ jobs:
       matrix:
         ruby_version:
           - "3.2"
+          - "4.0"
         include:
           - ruby_version: '3.2'
             puppet_gem_version: '~> 8.0'
+          - ruby_version: '4.0'
+            puppet_gem_version: '~> 9.0'
         runs_on:
           - "ubuntu-latest"
           - "windows-latest"
@@ -32,9 +35,12 @@ jobs:
       matrix:
         ruby_version:
           - "3.2"
+          - "4.0"
         include:
           - ruby_version: '3.2'
             puppet_gem_version: 'https://github.com/puppetlabs/puppet' # puppet8'
+          - ruby_version: '4.0'
+            puppet_gem_version: '~> 9.0'
         runs_on:
           - "ubuntu-latest"
           - "windows-latest"
diff --git a/Gemfile b/Gemfile
index 00823ad9..c202b28e 100644
--- a/Gemfile
+++ b/Gemfile
@@ -1,10 +1,17 @@
 # frozen_string_literal: true
 
-source ENV['GEM_SOURCE'] || "https://rubygems.org"
+# For puppetcore, set GEM_SOURCE_PUPPETCORE = 'https://rubygems-puppetcore.puppet.com'
+gemsource_default = ENV['GEM_SOURCE'] || "https://rubygems.org"
+gemsource_puppetcore = if !ENV['PUPPET_FORGE_TOKEN'].to_s.empty?
+                         'https://rubygems-puppetcore.puppet.com'
+                       else
+                         ENV['GEM_SOURCE_PUPPETCORE'] || gemsource_default
+                       end
+source gemsource_default
 
 gemspec
 
-def location_for(place_or_version, fake_version = nil)
+def location_for(place_or_version, fake_version = nil, opts = {})
   git_url_regex = %r{\A(?<url>(https?|git)[:@][^#]*)(#(?<branch>.*))?}
   file_url_regex = %r{\Afile:\/\/(?<path>.*)}
 
@@ -13,12 +20,12 @@ def location_for(place_or_version, fake_version = nil)
   elsif place_or_version && (file_url = place_or_version.match(file_url_regex))
     ['>= 0', { path: File.expand_path(file_url[:path]), require: false }]
   else
-    [place_or_version, { require: false }]
+    [place_or_version, { require: false }.merge(opts)]
   end
 end
 
 group :development do
-  gem 'puppet', *location_for(ENV['PUPPET_GEM_VERSION'])
+  gem 'puppet', *location_for(ENV.fetch('PUPPET_GEM_VERSION', nil), nil, { source: gemsource_puppetcore })
 
   gem 'json_spec', '~> 1.1', '>= 1.1.5'
 
@@ -48,6 +55,8 @@ group :development do
 end
 
 group :acceptance do
+  # Source bolt from puppetcore too, since it's a transitive puppet_litmus dependency.
+  gem 'bolt', *location_for(ENV.fetch('BOLT_GEM_VERSION', nil), nil, { source: gemsource_puppetcore })
   gem 'puppet_litmus'
   gem 'net-ssh'
 end