diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index e616f56d2ed07f..9301a1edd6d849 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -115,17 +115,13 @@ jobs:
     - uses: actions/checkout@v4
     - name: setup SDK
       shell: powershell
-      run: |-
-        ci/install-sdk.ps1
-        echo "MSYSTEM=mingw64" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
-        echo "$(pwd)/git-sdk/usr/bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        echo "$(pwd)/git-sdk/mingw64/bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+      run: ci/install-sdk.ps1
     - name: build
-      shell: bash
+      shell: powershell
       env:
         HOME: ${{runner.workspace}}
         NO_PERL: 1
-      run: . /etc/profile && ci/make-test-artifacts.sh artifacts
+      run: git-sdk/usr/bin/bash.exe -l -c 'ci/make-test-artifacts.sh artifacts'
     - name: zip up tracked files
       run: git archive -o artifacts/tracked.tar.gz HEAD
     - name: upload tracked files and build artifacts
@@ -155,14 +151,10 @@ jobs:
       run: tar xf artifacts.tar.gz && tar xf tracked.tar.gz
     - name: setup SDK
       shell: powershell
-      run: |-
-        ci/install-sdk.ps1
-        echo "MSYSTEM=mingw64" | Out-File -FilePath $env:GITHUB_ENV -Encoding utf8 -Append
-        echo "$(pwd)/git-sdk/usr/bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
-        echo "$(pwd)/git-sdk/mingw64/bin" | Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+      run: ci/install-sdk.ps1
     - name: test
-      shell: bash
-      run: . /etc/profile && ci/run-test-slice.sh ${{matrix.nr}} 10
+      shell: powershell
+      run: git-sdk/usr/bin/bash.exe -l -c 'ci/run-test-slice.sh ${{matrix.nr}} 10'
     - name: print test failures
       if: failure() && env.FAILED_TEST_ARTIFACTS != ''
       shell: bash