diff --git a/.github/workflows/daily_unit_tests_with_nightly_puppet_gem.yaml b/.github/workflows/daily_unit_tests_with_nightly_puppet_gem.yaml
index b31bf18..bf07dc5 100644
--- a/.github/workflows/daily_unit_tests_with_nightly_puppet_gem.yaml
+++ b/.github/workflows/daily_unit_tests_with_nightly_puppet_gem.yaml
@@ -1,58 +1,58 @@
 ---
 name: '[Daily] Unit Tests with nightly Puppet gem'
 
 on:
   schedule:
     - cron: '0 5 * * 1-5'
 
 jobs:
   daily_unit_tests_with_nightly_puppet_gem:
     name: ${{ matrix.os_type }} / Puppet${{ matrix.puppet_version }} gem / Ruby ${{ matrix.ruby }} 
     strategy:
       matrix:
-        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2019' ]
+        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2016' ]
         puppet_version: [ 5, 6, 7 ]
         include:
           - puppet_version: 5
             ruby: 2.4
           - puppet_version: 6
             ruby: 2.5
           - puppet_version: 7
             ruby: 2.7
 
           - os: 'ubuntu-18.04'
             os_type: 'Linux'
             env_set_cmd: 'export '
             gem_file: 'puppet-latest.gem'
           - os: 'macos-10.15'
             os_type: 'macOS'
             env_set_cmd: 'export '
             gem_file: 'puppet-latest-universal-darwin.gem'
-          - os: 'windows-2019'
+          - os: 'windows-2016'
             os_type: 'Windows'
             env_set_cmd: '$env:'
             gem_file: 'puppet-latest-x64-mingw32.gem'
 
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
 
       - name: Install ruby version ${{ matrix.ruby }}
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
 
       - name: Install the latest nightly build of puppet${{ matrix.puppet_version }} gem
         run: |
           curl http://nightlies.puppet.com/downloads/gems/puppet${{ matrix.puppet_version }}-nightly/${{ matrix.gem_file }} --output puppet.gem
           gem install puppet.gem -N
 
       - name: Prepare testing environment with bundler
         run: |
           bundle config set system 'true'
           ${{ matrix.env_set_cmd }}PUPPET_GEM_VERSION=$(ruby -e 'puts /puppet\s+\((.+)\)/.match(`gem list -eld puppet`)[1]')
           bundle update --jobs 4 --retry 3
 
       - name: Run unit tests
         run: bundle exec rake parallel_spec
diff --git a/.github/workflows/unit_tests_with_nightly_puppet_gem.yaml b/.github/workflows/unit_tests_with_nightly_puppet_gem.yaml
index 8c5d909..b408ee8 100644
--- a/.github/workflows/unit_tests_with_nightly_puppet_gem.yaml
+++ b/.github/workflows/unit_tests_with_nightly_puppet_gem.yaml
@@ -1,60 +1,60 @@
 ---
 name: Unit Tests with nightly Puppet gem
 
 on:
   push:
     branches: [ main ]
   pull_request:
     branches: [ main ]
 
 jobs:
   unit_tests_with_nightly_puppet_gem:
     name: ${{ matrix.os_type }} / Puppet${{ matrix.puppet_version }} gem / Ruby ${{ matrix.ruby }}
     strategy:
       matrix:
-        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2019' ]
+        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2016' ]
         puppet_version: [ 5, 6, 7 ]
         include:
           - puppet_version: 5
             ruby: 2.4
           - puppet_version: 6
             ruby: 2.5
           - puppet_version: 7
             ruby: 2.7
 
           - os: 'ubuntu-18.04'
             os_type: 'Linux'
             env_set_cmd: 'export '
             gem_file: 'puppet-latest.gem'
           - os: 'macos-10.15'
             os_type: 'macOS'
             env_set_cmd: 'export '
             gem_file: 'puppet-latest-universal-darwin.gem'
-          - os: 'windows-2019'
+          - os: 'windows-2016'
             os_type: 'Windows'
             env_set_cmd: '$env:'
             gem_file: 'puppet-latest-x64-mingw32.gem'
 
     runs-on: ${{ matrix.os }}
     steps:
       - name: Checkout current PR code
         uses: actions/checkout@v2
 
       - name: Install ruby version ${{ matrix.ruby }}
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
 
       - name: Install the latest nightly build of puppet${{ matrix.puppet_version }} gem
         run: |
           curl http://nightlies.puppet.com/downloads/gems/puppet${{ matrix.puppet_version }}-nightly/${{ matrix.gem_file }} --output puppet.gem
           gem install puppet.gem -N
 
       - name: Prepare testing environment with bundler
         run: |
           bundle config set system 'true'
           ${{ matrix.env_set_cmd }}PUPPET_GEM_VERSION=$(ruby -e 'puts /puppet\s+\((.+)\)/.match(`gem list -eld puppet`)[1]')
           bundle update --jobs 4 --retry 3
 
       - name: Run unit tests
         run: bundle exec rake parallel_spec
diff --git a/.github/workflows/unit_tests_with_released_puppet_gem.yaml b/.github/workflows/unit_tests_with_released_puppet_gem.yaml
index 065e2b9..47385ac 100644
--- a/.github/workflows/unit_tests_with_released_puppet_gem.yaml
+++ b/.github/workflows/unit_tests_with_released_puppet_gem.yaml
@@ -1,48 +1,48 @@
 ---
 name: Unit Tests with released Puppet gem
 
 on:
   push:
     branches: [ main ]
   pull_request:
     branches: [ main ]
 
 jobs:
   unit_tests_with_released_puppet_gem:
     name: ${{ matrix.os_type }} / Puppet${{ matrix.puppet_version }} gem / Ruby ${{ matrix.ruby }} 
     strategy:
       matrix:
-        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2019' ]
+        os: [ 'ubuntu-18.04', 'macos-10.15', 'windows-2016' ]
         puppet_version: [ 5, 6 ]
         include:
           - puppet_version: 5
             ruby: 2.4
           - puppet_version: 6
             ruby: 2.5
 
           - os: 'ubuntu-18.04'
             os_type: 'Linux'
           - os: 'macos-10.15'
             os_type: 'macOS'
-          - os: 'windows-2019'
+          - os: 'windows-2016'
             os_type: 'Windows'
 
     runs-on: ${{ matrix.os }}
     env:
       PUPPET_GEM_VERSION: ~> ${{ matrix.puppet_version }}.0
     steps:
       - name: Checkout current PR code
         uses: actions/checkout@v2
 
       - name: Install ruby version ${{ matrix.ruby }}
         uses: ruby/setup-ruby@v1
         with:
           ruby-version: ${{ matrix.ruby }}
 
       - name: Prepare testing environment with bundler
         run: |
           bundle config set system 'true'
           bundle update --jobs 4 --retry 3
 
       - name: Run unit tests
         run: bundle exec rake parallel_spec