diff --git a/apps/counter/api/views.py b/apps/counter/api/views.py
index cf8db64..8efd8cf 100644
--- a/apps/counter/api/views.py
+++ b/apps/counter/api/views.py
@@ -90,7 +90,7 @@ class DeviceLogStatisticAPIView(APIView, RoleMixin):
         tz = pytz.timezone("UTC")
         today = datetime.now(tz).date()
 
-        # calc monthly count, put it in redis as cache.
+        # calc month_ago_count, put it in redis as cache.
         if cache.get('month_ago_count'):
             month_ago_count = cache.get('month_ago_count')
         else:
@@ -105,7 +105,7 @@ class DeviceLogStatisticAPIView(APIView, RoleMixin):
                 month_ago_count = total_count - one_month_ago_count
             else:
                 month_ago_count = 0
-            cache.set('monthly_count', month_ago_count, 60 * 60)
+            cache.set('month_ago_count', month_ago_count, 60 * 60)
 
         # calc daily count, put it in redis as cache.
         if cache.get('daily_count'):