diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 1bd8566fc..f1a0202b3 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -10,19 +10,19 @@ jobs:
   osx:
     runs-on: macos-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Build
         run: bash tools/gha_osx.sh
   windows:
     runs-on: windows-2022
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Add msbuild to PATH
         uses: microsoft/setup-msbuild@v1.0.2
-      - uses: conda-incubator/setup-miniconda@v2
+      - uses: conda-incubator/setup-miniconda@v3
         with:
           auto-update-conda: true
-          python-version: 3.8
+          python-version: 3.12
           channels: conda-forge
           channel-priority: strict
       - name: Build
@@ -32,7 +32,7 @@ jobs:
     if: ${{ github.event_name }} == 'push'
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
+      - uses: actions/checkout@v4
       - name: Install and Build 🔧
         run: bash tools/gha_deploydocs.sh
       - name: Upload to github pages 🚀
diff --git a/tools/gha_windows-2019.ps1 b/tools/gha_windows-2019.ps1
index 7c39c3adf..8693766fa 100644
--- a/tools/gha_windows-2019.ps1
+++ b/tools/gha_windows-2019.ps1
@@ -12,6 +12,7 @@ cmake `
     -A x64 `
     -DCMAKE_PREFIX_PATH=C:\Miniconda\envs\pagmo `
     -DCMAKE_INSTALL_PREFIX=C:\Miniconda\envs\pagmo `
+    -DCMAKE_UNITY_BUILD=ON `
     -DBoost_NO_BOOST_CMAKE=ON `
     -DPAGMO_WITH_EIGEN3=ON `
     -DPAGMO_WITH_IPOPT=ON `