diff --git a/support/download/helpers b/support/download/helpers
index 90a7d6c1ec..265685eff5 100755
--- a/support/download/helpers
+++ b/support/download/helpers
@@ -53,6 +53,9 @@ mk_tar_gz() {
     tmp="$(mktemp --tmpdir="$(pwd)")"
     pushd "${in_dir}" >/dev/null
 
+    # Enforce group/others mode bits
+    chmod -R go-wx+X .
+
     # Establish list
     find . -not -type d -and -not \( -false "${find_opts[@]}" \) >"${tmp}.list"
     # Sort list for reproducibility