diff --git a/core/rawdb/chain_iterator.go b/core/rawdb/chain_iterator.go
index f8cc2f54b5..3cd7a3214d 100644
--- a/core/rawdb/chain_iterator.go
+++ b/core/rawdb/chain_iterator.go
@@ -17,7 +17,6 @@
 package rawdb
 
 import (
-	"math"
 	"runtime"
 	"sync/atomic"
 	"time"