diff --git a/.github/workflows/Test.yml b/.github/workflows/Test.yml
index 6c68278..416cc33 100644
--- a/.github/workflows/Test.yml
+++ b/.github/workflows/Test.yml
@@ -397,6 +397,9 @@ jobs:
     - shell: msys2 {0}
       run: |
         cygpath -m /
+    - name: MSYS2_ROOT
+      run: |
+        $Env:MSYS2_ROOT
     - shell: pwsh
       run: |
         $Env:MSYS2_ROOT = msys2 -c 'cygpath -m /'
diff --git a/main.js b/main.js
index 8598a11..44a9d77 100644
--- a/main.js
+++ b/main.js
@@ -259,6 +259,7 @@ async function run() {
     core.addPath(pathDir);
 
     core.exportVariable('MSYSTEM', input.msystem);
+    core.exportVariable('MSYS2_ROOT', msysRootDir);
 
     const packageCache = new PackageCache(msysRootDir, input);