diff --git a/engine/api/src/org/apache/cloudstack/storage/command/DettachAnswer.java b/engine/api/src/org/apache/cloudstack/storage/command/DettachAnswer.java
index 9019e0cfa59..6606a7fd743 100644
--- a/engine/api/src/org/apache/cloudstack/storage/command/DettachAnswer.java
+++ b/engine/api/src/org/apache/cloudstack/storage/command/DettachAnswer.java
@@ -26,8 +26,9 @@ public class DettachAnswer extends Answer {
     public DettachAnswer() {
         super(null);
     }
-    
+
     public DettachAnswer(DiskTO disk) {
+        super(null);
         this.setDisk(disk);
     }
     public DettachAnswer(String errMsg) {