diff --git a/core/src/main/java/com/taobao/arthas/core/advisor/AdviceListenerManager.java b/core/src/main/java/com/taobao/arthas/core/advisor/AdviceListenerManager.java
index ab710776d..f78b2a870 100644
--- a/core/src/main/java/com/taobao/arthas/core/advisor/AdviceListenerManager.java
+++ b/core/src/main/java/com/taobao/arthas/core/advisor/AdviceListenerManager.java
@@ -100,7 +100,7 @@ public class AdviceListenerManager {
         }, 3, 3, TimeUnit.SECONDS);
     }
 
-    static private ConcurrentWeakKeyHashMap<ClassLoader, ClassLoaderAdviceListenerManager> adviceListenerMap = new ConcurrentWeakKeyHashMap<ClassLoader, ClassLoaderAdviceListenerManager>();
+    private static final ConcurrentWeakKeyHashMap<ClassLoader, ClassLoaderAdviceListenerManager> adviceListenerMap = new ConcurrentWeakKeyHashMap<ClassLoader, ClassLoaderAdviceListenerManager>();
 
     static class ClassLoaderAdviceListenerManager {
         private ConcurrentHashMap<String, List<AdviceListener>> map = new ConcurrentHashMap<String, List<AdviceListener>>();