diff --git a/miner/worker.go b/miner/worker.go
index f680702814..a642d46b6f 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -125,7 +125,7 @@ func (env *environment) discard() {
 	if env.state == nil {
 		return
 	}
-	env.state.StopPrefetcher()
+	//env.state.StopPrefetcher()
 }
 
 // task contains all information for consensus engine sealing and result submitting.
@@ -711,7 +711,7 @@ func (w *worker) makeEnv(parent *types.Header, header *types.Header, coinbase co
 	if err != nil {
 		return nil, err
 	}
-	state.StartPrefetcher("miner")
+	//state.StartPrefetcher("miner")
 
 	// Note the passed coinbase may be different with header.Coinbase.
 	env := &environment{