diff --git a/miner/worker.go b/miner/worker.go
index c5240a6d6a..9085daee10 100644
--- a/miner/worker.go
+++ b/miner/worker.go
@@ -67,9 +67,6 @@ const (
 	// chainHeadChanSize is the size of channel listening to ChainHeadEvent.
 	chainHeadChanSize = 10
 
-	// chainSideChanSize is the size of channel listening to ChainSideEvent.
-	chainSideChanSize = 10
-
 	// resubmitAdjustChanSize is the size of resubmitting interval adjustment channel.
 	resubmitAdjustChanSize = 10
 
@@ -210,8 +207,6 @@ type worker struct {
 	txsSub       event.Subscription
 	chainHeadCh  chan core.ChainHeadEvent
 	chainHeadSub event.Subscription
-	chainSideCh  chan core.ChainSideEvent
-	chainSideSub event.Subscription
 
 	// Channels
 	newWorkCh          chan *newWorkReq