diff --git a/.github/workflows/build.yaml b/.github/workflows/build.yaml
index 67bd3ac..9e3d223 100644
--- a/.github/workflows/build.yaml
+++ b/.github/workflows/build.yaml
@@ -81,9 +81,14 @@ jobs:
           prev_sha=$(git rev-list -1 "$prev_tag")
           echo "Previous tag ${prev_tag} (${prev_sha})"
           current_tag=${GITHUB_REF#refs/tags/}
+          if [ -z "$current_tag" ]; then
+            echo "Current ref is not a tag, skipping upload."
+            echo "skip=true" >> "$GITHUB_ENV"
+            exit 0
+          fi
           current_sha=$(git rev-list -1 "$current_tag")
           echo "Current tag ${current_tag} (${current_sha})"
-          if [ -z ${current_tag} ] || [ "$current_sha" = "$prev_sha" ]; then
+          if [ "$current_sha" = "$prev_sha" ]; then
             echo "Skip upload"
             echo "skip=true" >> "$GITHUB_ENV"
           else