diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index 6e63341..0029b2c 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -231,6 +231,7 @@ jobs:
           echo "TOIT_GIT_VERSION=${{ github.event.inputs.toit-version }}" >> $GITHUB_ENV
 
       - name: Fetch the Toit repository
+        shell: bash
         run: |
           # We allow the workflow dispatch to override the checked out branch.
           # Note that we set the TOIT_GIT_VERSION env variable. The checked out branch