diff --git a/chain/sync.go b/chain/sync.go
index b83709387..68435a011 100644
--- a/chain/sync.go
+++ b/chain/sync.go
@@ -507,7 +507,7 @@ func (syncer *Syncer) collectHeaders(from *types.TipSet, to *types.TipSet) ([]*t
 		log.Warn("syncing local: ", at)
 		ts, err := syncer.store.LoadTipSet(at)
 		if err != nil {
-			if err == bstore.ErrNotFound {
+			if xerrors.Is(err, bstore.ErrNotFound) {
 				log.Info("tipset not found locally, starting sync: ", at)
 				break
 			}
diff --git a/chain/sync_test.go b/chain/sync_test.go
index 47b8f4ec3..8267b2389 100644
--- a/chain/sync_test.go
+++ b/chain/sync_test.go
@@ -283,11 +283,8 @@ func TestSyncMining(t *testing.T) {
 
 	require.NoError(t, tu.mn.LinkAll())
 	tu.connect(client, 0)
-	fmt.Println("waiting for sync...")
 	tu.waitUntilSync(0, client)
 
-	fmt.Println("after wait until sync")
-
 	//tu.checkHeight("client", client, H)
 
 	tu.compareSourceState(client)
diff --git a/chain/types/blockheader.go b/chain/types/blockheader.go
index 4d7bf6f2f..2821de0b5 100644
--- a/chain/types/blockheader.go
+++ b/chain/types/blockheader.go
@@ -174,3 +174,7 @@ func PowerCmp(eproof ElectionProof, mpow, totpow BigInt) bool {
 	hp := BigFromBytes(h[:])
 	return hp.LessThan(out)
 }
+
+func (t *Ticket) Equals(ot *Ticket) bool {
+	return bytes.Equal(t.VDFResult, ot.VDFResult)
+}
diff --git a/chain/types/tipset.go b/chain/types/tipset.go
index 5484b476a..3337a823e 100644
--- a/chain/types/tipset.go
+++ b/chain/types/tipset.go
@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"encoding/json"
 	"fmt"
+	"sort"
 
 	"github.com/ipfs/go-cid"
 	logging "github.com/ipfs/go-log"
@@ -39,13 +40,33 @@ func (ts *TipSet) UnmarshalJSON(b []byte) error {
 		return err
 	}
 
-	ts.cids = ets.Cids
-	ts.blks = ets.Blocks
-	ts.height = ets.Height
+	ots, err := NewTipSet(ets.Blocks)
+	if err != nil {
+		return err
+	}
+
+	*ts = *ots
+
 	return nil
 }
 
+func tipsetSortFunc(blks []*BlockHeader) func(i, j int) bool {
+	return func(i, j int) bool {
+		ti := blks[i].LastTicket()
+		tj := blks[j].LastTicket()
+
+		if ti.Equals(tj) {
+			log.Warn("blocks have same ticket")
+			return blks[i].Cid().KeyString() < blks[j].Cid().KeyString()
+		}
+
+		return ti.Less(tj)
+	}
+}
+
 func NewTipSet(blks []*BlockHeader) (*TipSet, error) {
+	sort.Slice(blks, tipsetSortFunc(blks))
+
 	var ts TipSet
 	ts.cids = []cid.Cid{blks[0].Cid()}
 	ts.blks = blks