diff --git a/.github/workflows/test-windows.yml b/.github/workflows/test-windows.yml
index 7ae26b8834c..83dc5748b0b 100644
--- a/.github/workflows/test-windows.yml
+++ b/.github/workflows/test-windows.yml
@@ -52,6 +52,11 @@ jobs:
         python-version: ${{ matrix.python-version }}
         architecture: ${{ matrix.architecture }}
 
+    - name: Set up TCL
+      if: "contains(matrix.python-version, 'pypy')"
+      run: Write-Host "::set-env name=TCL_LIBRARY::$env:pythonLocation\tcl\tcl8.5"
+      shell: pwsh
+
     - name: Print build system information
       run: python .github/workflows/system-info.py