diff --git a/rsync-antora-reference/src/rsync_docs.sh b/rsync-antora-reference/src/rsync_docs.sh
index 8de9aa6..8a9fd2b 100755
--- a/rsync-antora-reference/src/rsync_docs.sh
+++ b/rsync-antora-reference/src/rsync_docs.sh
@@ -92,6 +92,8 @@ __rsync_docs() {
     rsync_opts="-c $rsync_opts$(find $local_path -mindepth 1 -maxdepth 1 \! -name 404.html \! -name '.*' -type f -printf ' --include /%P')"
     rsync_opts="$rsync_opts$(find $local_path -mindepth 1 -maxdepth 1 -type d \! -name _ -printf ' --include /%P --include /%P/**') --exclude **"
   fi
+  # Disable filename expansion (globbing)
+  # https://www.gnu.org/software/bash/manual/html_node/The-Set-Builtin.html
   set -f
   rsync $rsync_opts -e "ssh -i $ssh_private_key_path" $local_path/ "$ssh_host:$ssh_host_path"
   set +f