diff --git a/action.yaml b/action.yaml
index 2b36d43..f485bf7 100644
--- a/action.yaml
+++ b/action.yaml
@@ -45,7 +45,12 @@ runs:
           # path. Legacy archives embed the absolute path of the run that
           # saved them; fall back to extracting them to "/" (status quo,
           # they are TTL-pruned within the retention window anyway).
-          FIRST_ENTRY=$(tar -tf "$ARCHIVE" 2>/dev/null | head -1)
+          # NOTE: `|| true` is mandatory — act runs step scripts with
+          # `bash -e -o pipefail`, and `head -1` closes the pipe after the
+          # first line, so tar dies with SIGPIPE (141) and pipefail turns
+          # that into a step failure (restore only ever "worked" before
+          # this detection line existed).
+          FIRST_ENTRY=$(tar -tf "$ARCHIVE" 2>/dev/null | head -1 || true)
           if [ "${FIRST_ENTRY%%/*}" = "$(basename "$EXPANDED_PATH")" ]; then
             echo "Restoring to: $(dirname "$EXPANDED_PATH")"
             tar -xf "$ARCHIVE" -C "$(dirname "$EXPANDED_PATH")" 2>/dev/null