diff --git a/chain/store/events.go b/chain/store/events.go
index 1ac794fa0..12ac87088 100644
--- a/chain/store/events.go
+++ b/chain/store/events.go
@@ -28,21 +28,12 @@ type eventChainStore interface {
 }
 
 type Events struct {
-	cs           eventChainStore
-	gcConfidence uint64
+	cs eventChainStore
 
 	tsc *tipSetCache
 	lk  sync.Mutex
 
-	ctr triggerId
-
-	// ChainAt
-
-	heightTriggers map[triggerId]*heightHandler
-
-	htTriggerHeights map[triggerH][]triggerId
-	htHeights        map[msgH][]triggerId
-
+	heightEvents
 	calledEvents
 }
 
@@ -52,18 +43,23 @@ func NewEvents(cs eventChainStore) *Events {
 	tsc := newTSCache(gcConfidence)
 
 	e := &Events{
-		cs:           cs,
-		gcConfidence: uint64(gcConfidence),
+		cs: cs,
 
 		tsc: tsc,
 
-		heightTriggers:   map[uint64]*heightHandler{},
-		htTriggerHeights: map[uint64][]uint64{},
-		htHeights:        map[uint64][]uint64{},
+		heightEvents: heightEvents{
+			tsc:          tsc,
+			gcConfidence: uint64(gcConfidence),
+
+			heightTriggers:   map[uint64]*heightHandler{},
+			htTriggerHeights: map[uint64][]uint64{},
+			htHeights:        map[uint64][]uint64{},
+		},
 
 		calledEvents: calledEvents{
-			cs:  cs,
-			tsc: tsc,
+			cs:           cs,
+			tsc:          tsc,
+			gcConfidence: uint64(gcConfidence),
 
 			confQueue:   map[triggerH]map[msgH][]*queuedEvent{},
 			revertQueue: map[msgH][]triggerH{},
diff --git a/chain/store/events_called.go b/chain/store/events_called.go
index 685a64f09..114a73cda 100644
--- a/chain/store/events_called.go
+++ b/chain/store/events_called.go
@@ -50,8 +50,9 @@ type queuedEvent struct {
 }
 
 type calledEvents struct {
-	cs  eventChainStore
-	tsc *tipSetCache
+	cs           eventChainStore
+	tsc          *tipSetCache
+	gcConfidence uint64
 
 	lk sync.Mutex
 
diff --git a/chain/store/events_height.go b/chain/store/events_height.go
index 98ea1125e..62e3681ce 100644
--- a/chain/store/events_height.go
+++ b/chain/store/events_height.go
@@ -2,9 +2,26 @@ package store
 
 import (
 	"github.com/filecoin-project/go-lotus/chain/types"
+	"sync"
 )
 
-func (e *Events) headChangeAt(rev, app []*types.TipSet) error {
+type heightEvents struct {
+	lk           sync.Mutex
+	tsc          *tipSetCache
+	gcConfidence uint64
+
+	ctr triggerId
+
+	heightTriggers map[triggerId]*heightHandler
+
+	htTriggerHeights map[triggerH][]triggerId
+	htHeights        map[msgH][]triggerId
+}
+
+func (e *heightEvents) headChangeAt(rev, app []*types.TipSet) error {
+	e.lk.Lock()
+	defer e.lk.Unlock()
+
 	// highest tipset is always the first (see cs.ReorgOps)
 	newH := app[0].Height()
 
@@ -55,7 +72,7 @@ func (e *Events) headChangeAt(rev, app []*types.TipSet) error {
 	return nil
 }
 
-func (e *Events) ChainAt(hnd HeightHandler, rev RevertHandler, confidence int, h uint64) error {
+func (e *heightEvents) ChainAt(hnd HeightHandler, rev RevertHandler, confidence int, h uint64) error {
 	e.lk.Lock()
 	defer e.lk.Unlock()