diff --git a/.github/workflows/swift_package_test.yml b/.github/workflows/swift_package_test.yml
index feed3e8e..8ac2b6ce 100644
--- a/.github/workflows/swift_package_test.yml
+++ b/.github/workflows/swift_package_test.yml
@@ -684,10 +684,16 @@ jobs:
       - name: Determine script-root path
         id: script_path
         run: |
+          if ("${{ inputs.enable_windows_docker }}" -eq "true") {
+            $source = "C:\source"
+          } else {
+            $source = $env:GITHUB_WORKSPACE
+          }
+
           if ("${{ github.repository }}" -eq "swiftlang/github-workflows") {
-            echo "root=$env:GITHUB_WORKSPACE" >> $env:GITHUB_OUTPUT
+            echo "root=$source" >> $env:GITHUB_OUTPUT
           } else {
-            echo "root=$env:GITHUB_WORKSPACE/github-workflows" >> $env:GITHUB_OUTPUT
+            echo "root=$source/github-workflows" >> $env:GITHUB_OUTPUT
           }
       - name: Provide token
         if: ${{ inputs.needs_token }}