diff --git a/eth/backend.go b/eth/backend.go
index 168bb3b552..e670a58617 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -334,6 +334,7 @@ func (self *Ethereum) SetEtherbase(etherbase common.Address) {
 	self.miner.SetEtherbase(etherbase)
 }
 
+// ValidateMiner checks if node's address is in set of validators
 func (s *Ethereum) ValidateMiner() (bool, error) {
 	eb, err := s.Etherbase()
 	if err != nil {
@@ -353,20 +354,9 @@ func (s *Ethereum) ValidateMiner() (bool, error) {
 	} else {
 		return false, fmt.Errorf("Only verify miners in Clique protocol")
 	}
-	
 	return true, nil
 }
 
-func (s *Ethereum) Checkpoint() bool {
-	number := s.blockchain.CurrentHeader().Number.Uint64()
-	return number%s.chainConfig.Clique.Epoch == 1 || number == 0
-}
-
-func (s *Ethereum) Checkpoint() bool {
-	number := s.blockchain.CurrentHeader().Number.Uint64()
-	return number%s.chainConfig.Clique.Epoch == 1
-}
-
 func (s *Ethereum) StartMining(local bool) error {
 	eb, err := s.Etherbase()
 	if err != nil {