diff --git a/testcase/src/main/java/com/alibaba/arthas/Test.java b/testcase/src/main/java/com/alibaba/arthas/Test.java
index 25e3c2023..f09986af9 100644
--- a/testcase/src/main/java/com/alibaba/arthas/Test.java
+++ b/testcase/src/main/java/com/alibaba/arthas/Test.java
@@ -43,7 +43,7 @@ public class Test {
             list.get(random).setName(null);
             test(list);
             list.get(random).setName(name);
-            Thread.sleep(1000l);
+            Thread.sleep(1000L);
         }
     }