diff --git a/mvcc/backend/backend.go b/mvcc/backend/backend.go
index 924cc8c68e5..f7d9e60c2e7 100644
--- a/mvcc/backend/backend.go
+++ b/mvcc/backend/backend.go
@@ -291,6 +291,8 @@ func (b *backend) Defrag() error {
 }
 
 func (b *backend) defrag() error {
+	now := time.Now()
+	
 	// TODO: make this non-blocking?
 	// lock batchTx to ensure nobody is using previous tx, and then
 	// close previous ongoing tx.