diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 8e8677f3..5e32287d 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -44,6 +44,7 @@ jobs:
           /opt/build.sh all
       - 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