diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 551656b..4bc5dce 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -72,6 +72,19 @@ jobs:
       env:
         MSYSTEM: MINGW32
 
+  shell:
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v1
+    - name: install deps
+      run: npm ci
+    - name: run action
+      uses: ./
+    - shell: ./msys2.cmd {0}
+      run: |
+        uname -a
+        pacman -Syu --noconfirm
+
   msystem:
     strategy:
       matrix:
diff --git a/index.js b/index.js
index c3263b1..3f55528 100644
--- a/index.js
+++ b/index.js
@@ -34,12 +34,20 @@ async function run() {
 
     let cmd = path.join(dest, 'msys2do.cmd');
     fs.writeFileSync(cmd, [
-      'setlocal',
-      '@echo off',
-      'IF NOT DEFINED MSYS2_PATH_TYPE set MSYS2_PATH_TYPE=' + core.getInput('path-type'),
+      `setlocal`,
+      `@echo off`,
+      `IF NOT DEFINED MSYS2_PATH_TYPE set MSYS2_PATH_TYPE=` + core.getInput('path-type'),
       `%~dp0\\msys64\\usr\\bin\\bash.exe -ilc "cd $OLDPWD && %*"`
     ].join('\r\n'));
 
+    fs.writeFileSync('C:/hostedtoolcache/windows/Python/3.6.8/x64/msys2.cmd', [
+      `setlocal`,
+      `@echo off`,
+      `set "args=%*"`,
+      `set "args=%args:\\=/%"`,
+      cmd + ` %args%`
+    ].join('\r\n'));
+
     core.addPath(dest);
 
     core.exportVariable('MSYSTEM', core.getInput('msystem'));