diff --git a/.github/workflows/tests.yml b/.github/workflows/tests.yml
index a7d417d..6547ab8 100644
--- a/.github/workflows/tests.yml
+++ b/.github/workflows/tests.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [windows-latest, windows-2019]
-        python-version: ["3.9", "3.10", "3.11"]
+        python-version: ["3.9", "3.10", "3.11", "3.12"]
         architecture: ["x64", "x86"]
     steps:
       - uses: actions/checkout@v3
@@ -23,7 +23,7 @@ jobs:
           python-version: ${{ matrix.python-version }}
       - name: install packages
         run: |
-          pip install comtypes
+          pip install https://github.com/enthought/comtypes/archive/refs/heads/main.zip
           pip install pytest
           pip install pytest-mock
       - name: run pytest