diff --git a/pom.xml b/pom.xml
index 18a340e..0acd0c0 100644
--- a/pom.xml
+++ b/pom.xml
@@ -27,7 +27,7 @@
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
         <maven.compiler.encoding>UTF-8</maven.compiler.encoding>
-        <mirai.CoreVersion>1.0.2</mirai.CoreVersion>
+        <mirai.CoreVersion>1.0.4</mirai.CoreVersion>
         <mirai.JaptVersion>1.1.1</mirai.JaptVersion>
         <kotlin.version>1.3.71</kotlin.version>
         <ktor.version>1.3.2</ktor.version>
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;