diff --git a/server/services/alertService.js b/server/services/alertService.js
index 26d712e..c9b875a 100644
--- a/server/services/alertService.js
+++ b/server/services/alertService.js
@@ -250,7 +250,11 @@ class AlertService {
       
       // PRIORITY 1: Device-specific filter (most important)
       if (rule.device_ids && rule.device_ids.length > 0) {
-        if (!rule.device_ids.includes(detection.device_id)) {
+        // Convert both device IDs to strings for consistent comparison
+        const deviceIdStr = String(detection.device_id);
+        const allowedDeviceIds = rule.device_ids.map(id => String(id));
+        
+        if (!allowedDeviceIds.includes(deviceIdStr)) {
           console.log(`❌ Rule "${rule.name}": Device ${detection.device_id} not in allowed devices [${rule.device_ids.join(', ')}]`);
           return false;
         } else {