diff --git a/vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java b/vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java
index 2135e2b1816..01bbf02a7b0 100644
--- a/vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java
+++ b/vmware-base/src/main/java/com/cloud/hypervisor/vmware/mo/VirtualMachineMO.java
@@ -2641,7 +2641,7 @@ public class VirtualMachineMO extends BaseMO {
                     VirtualDeviceBackingInfo backingInfo = ((VirtualDisk)device).getBacking();
                     if (backingInfo instanceof VirtualDiskFlatVer2BackingInfo) {
                         VirtualDiskFlatVer2BackingInfo diskBackingInfo = (VirtualDiskFlatVer2BackingInfo)backingInfo;
-                        disks.add(new Pair<Integer, ManagedObjectReference>(new Integer(device.getUnitNumber()), diskBackingInfo.getDatastore()));
+                        disks.add(new Pair<Integer, ManagedObjectReference>(new Integer(device.getKey()), diskBackingInfo.getDatastore()));
                     }
                 }
             }