diff --git a/src/main/java/net/lamgc/cgj/bot/cache/LocalHashCacheStore.java b/src/main/java/net/lamgc/cgj/bot/cache/LocalHashCacheStore.java
index 4ef6196..0fa9398 100644
--- a/src/main/java/net/lamgc/cgj/bot/cache/LocalHashCacheStore.java
+++ b/src/main/java/net/lamgc/cgj/bot/cache/LocalHashCacheStore.java
@@ -158,7 +158,7 @@ public class LocalHashCacheStore<T> implements CacheStore<T>, Cleanable {
         expireKeySet.forEach(cache::remove);
     }
 
-    public static class CacheObject<T> implements Comparable<CacheObject<T>> {
+    private static class CacheObject<T> implements Comparable<CacheObject<T>> {
 
         private final AtomicReference<T> value;
         private final AtomicReference<Date> expire;