diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 5e32287d..00ea9382 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -162,6 +162,7 @@ jobs:
 
     - name: Output build size
       id: output-sizes
+      shell: bash
       run: |
         . /opt/build.sh
         .github/workflows/getSize.sh "$BUILD_DIR"/src/pinetime-app-*.out >> $GITHUB_OUTPUT