diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index f52a42a2f..e93cad2aa 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -130,16 +130,22 @@ jobs:
          # ninja version to download. Default: 1.10.0
          version: 1.10.0
          dest: ${{ github.workspace }}/ninja_bin
+
+     - name: Add prebuilt llvm install dir to PATH
+       run: |
+         "${{ github.workspace }}/llvm-install-${{ env.LLVM_VER }}/bin\n" + (Get-Content $env:GITHUB_PATH -Raw) | Set-Content $env:GITHUB_PATH
+         Add-Content $env:GITHUB_ENV "CXX_COMPILER_BIN=${{ github.workspace }}/llvm-install-${{ env.LLVM_VER }}/bin"
+
      - name: Configure CMake
        env:
          CMAKE_PREFIX_PATH: ${{ github.workspace }}/llvm-install-${{ env.LLVM_VER }}
-       run: cmake -B build -G Ninja -DFINAL_STAGE=1 -DCMAKE_CXX_COMPILER=clang.exe -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=jakt-install
+       run: cmake -B build -G Ninja -DFINAL_STAGE=1 -DCMAKE_CXX_COMPILER=clang -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=jakt-install
 
      - name: Build Jakt Stage 1 Selfhost
        run: cmake --build build
 
      - name: Test Jakt Stage 1
-       run: .\build\bin\jakttest.exe
+       run: .\build\bin\jakttest.exe --cpp-compiler "$env:CXX_COMPILER_BIN/clang++.exe"
 
      # FIXME: Share this better with unix job?
      - name: Install jakt
@@ -151,7 +157,7 @@ jobs:
        run: |
          ./jakt-install/bin/jakt.exe --create TestProjectJakt
          cd TestProjectJakt
-         ../jakt-install/bin/jakt.exe -O src/main.jakt -o TestProjectJakt
+         ../jakt-install/bin/jakt.exe -O src/main.jakt -o TestProjectJakt -C "$CXX_COMPILER_BIN/clang-cl"
          if ! ./build/TestProjectJakt.exe | grep -q "Hello, World!";
          then
            echo "::error :^( failed, failing job"
@@ -161,6 +167,7 @@ jobs:
        working-directory: ${{ github.workspace }}
        shell: bash
        run: |
+         export PATH="$CXX_COMPILER_BIN:$PATH"
          ./jakt-install/bin/jakt.exe --create TestProjectCMake
          cd TestProjectCMake
          cmake -GNinja -B build \