diff --git a/.github/workflows/build_app.yml b/.github/workflows/build_app.yml
index 761ddea..c5d1aa7 100644
--- a/.github/workflows/build_app.yml
+++ b/.github/workflows/build_app.yml
@@ -69,7 +69,7 @@ jobs:
           echo "expr ${{ steps.current_commit.outputs.COMMIT_COUNT }} - $prev_commit_count"
           echo "$(expr ${{ steps.current_commit.outputs.COMMIT_COUNT }} - ${prev_commit_count})"
           echo "$(expr ${{ steps.current_commit.outputs.COMMIT_COUNT }} - $prev_commit_count)"
-          commit_count_diff=$(expr ${{ steps.current_commit.outputs.COMMIT_COUNT }} - $prev_commit_count)
+          commit_count_diff="$(expr ${{ steps.current_commit.outputs.COMMIT_COUNT }} - $prev_commit_count)"
           echo "commit_count_diff=$commit_count_diff"
           prev_release_sha=$(git rev-parse --short HEAD~$commit_count_diff)
           echo "PREV_RELEASE_SHA=$prev_release_sha"