diff --git a/docker-compose.yml b/docker-compose.yml
index 526450e4..c2059abf 100644
--- a/docker-compose.yml
+++ b/docker-compose.yml
@@ -23,6 +23,7 @@ services:
   redis:
     image: redis:7-alpine
     restart: always
+    command: redis-server --maxmemory 100mb --maxmemory-policy allkeys-lru
     ports:
       - "6380:6379"  # Use 6380 to avoid conflict with host Redis
     mem_limit: 128m
diff --git a/monitoring/prometheus/alert.rules.yml b/monitoring/prometheus/alert.rules.yml
index 7a87ac6c..eeddb658 100644
--- a/monitoring/prometheus/alert.rules.yml
+++ b/monitoring/prometheus/alert.rules.yml
@@ -140,7 +140,7 @@ groups:
           description: "Redis exporter cannot connect to Redis for 1 minute. Background tasks (emails, Celery) are not processing."
 
       - alert: RedisHighMemoryUsage
-        expr: redis_memory_used_bytes / redis_memory_max_bytes * 100 > 80
+        expr: redis_memory_max_bytes > 0 and redis_memory_used_bytes / redis_memory_max_bytes * 100 > 80
         for: 5m
         labels:
           severity: warning