diff --git a/.github/workflows/test-pack-lib.yml b/.github/workflows/test-pack-lib.yml
index 2a42237d..65397ec2 100644
--- a/.github/workflows/test-pack-lib.yml
+++ b/.github/workflows/test-pack-lib.yml
@@ -41,6 +41,7 @@ jobs:
       fail-fast: false
     steps:
       - name: "Process env string"
+        shell: bash
         run: |
           case "${{ matrix.runner }}" in
             ubuntu-latest)