diff --git a/.github/actions/2-build-bootstrap/action.yml b/.github/actions/2-build-bootstrap/action.yml
index a7becdcaeb8..f2de37ddf81 100644
--- a/.github/actions/2-build-bootstrap/action.yml
+++ b/.github/actions/2-build-bootstrap/action.yml
@@ -5,12 +5,15 @@ inputs:
     default: ''
   arch:
     required: false # Windows only
+  shell:
+    required: false
+    default: bash
 runs:
   using: composite
   steps:
 
     - name: Check CMake and ninja versions
-      shell: bash
+      shell: ${{ inputs.shell }}
       run: |
         set -eux
         cmake --version
@@ -27,4 +30,4 @@ runs:
         arch: ${{ inputs.arch }}
 
     - run: ../bootstrap-ldc/bin/ldc2 --version
-      shell: bash
+      shell: ${{ inputs.shell }}