diff --git a/.github/actions/ensure-image/action.yml b/.github/actions/ensure-image/action.yml
index 1b956ea..a816fb0 100644
--- a/.github/actions/ensure-image/action.yml
+++ b/.github/actions/ensure-image/action.yml
@@ -30,6 +30,7 @@ runs:
   steps:
     - id: ensure-image
       run: ./scripts/ensure-image.sh
+      shell: bash
       env:
         OS_CLIENT_CONFIG_FILE: ${{ inputs.os-client-config-file }}
         OS_CLOUD: ${{ inputs.os-cloud }}