diff --git a/pkg/util/azure/classic_snapshot.go b/pkg/util/azure/classic_snapshot.go
index 87a449fbfc..e5cb1d74b0 100644
--- a/pkg/util/azure/classic_snapshot.go
+++ b/pkg/util/azure/classic_snapshot.go
@@ -72,3 +72,7 @@ func (self *SClassicSnapshot) GetManagerId() string {
 func (self *SClassicSnapshot) GetRegionId() string {
 	return self.region.GetId()
 }
+
+func (self *SClassicSnapshot) GetDiskType() string {
+	return ""
+}