diff --git a/scripts/midi-bridge.py b/scripts/midi-bridge.py
index 6a3e9e0..e1fdfd9 100644
--- a/scripts/midi-bridge.py
+++ b/scripts/midi-bridge.py
@@ -6,7 +6,7 @@ to UDP ports for Pd (8081) and LED matrix visualization (8082).
 
 Writes metrics to /tmp/midi-stats.json for prometheus-exporter to collect.
 """
-import os, socket, time, select, pathlib, json
+import os, socket, time, select, pathlib, json, threading
 
 PD_HOST = os.environ.get("MIDI_BRIDGE_HOST", "127.0.0.1")
 PD_PORT = int(os.environ.get("MIDI_BRIDGE_PORT", "8081"))
@@ -22,7 +22,7 @@ last_status = 0
 last_note = 0
 last_velocity = 0
 last_time = 0.0
-_stats_lock = object()
+_stats_lock = threading.Lock()
 
 
 def _find_midi_dev():