diff --git a/test/rdp-access/rdp-access b/test/rdp-access/rdp-access
index 56a5296..a4de96a 100755
--- a/test/rdp-access/rdp-access
+++ b/test/rdp-access/rdp-access
@@ -191,6 +191,9 @@ start_ipv6_forward() {
         printf 'rdp-access: warning: socat unavailable; IPv6 forwarding disabled (IPv4 remains active)\n' >&2
         return 0
     fi
+    if [ -f "$ipv6_pid_file" ] && ipv6_process_matches "$(cat "$ipv6_pid_file" 2>/dev/null || true)" && ipv6_listener_active; then
+        return 0
+    fi
     if ipv6_listener_active; then
         # Do not kill an unrelated listener.  The operator can inspect it via
         # status; down only stops a PID that this helper started and verified.