diff --git a/scripts/gateway-watchdog.sh b/scripts/gateway-watchdog.sh
index 30200c7..83d4f5e 100755
--- a/scripts/gateway-watchdog.sh
+++ b/scripts/gateway-watchdog.sh
@@ -16,10 +16,11 @@ export PATH="/opt/homebrew/bin:/usr/local/bin:/usr/bin:/bin:$PATH"
 
 # === flock 防并发 ===
 LOCK_FILE="/tmp/gateway-watchdog.lock"
-exec 9>"$LOCK_FILE"
-if ! flock -n 9; then
+# macOS 无 flock，用 mkdir 做简易锁
+if ! mkdir "$LOCK_FILE" 2>/dev/null; then
     exit 0
 fi
+trap 'rmdir "$LOCK_FILE" 2>/dev/null' EXIT
 
 # === 配置 ===
 CHECK_WINDOW=120          # 检查最近多少秒的日志