diff --git a/build/params_mainnet.go b/build/params_mainnet.go
index db7166eec..195f0dd01 100644
--- a/build/params_mainnet.go
+++ b/build/params_mainnet.go
@@ -41,6 +41,8 @@ const UpgradeKumquatHeight = 170000
 const UpgradeCalicoHeight = 265200
 const UpgradePersianHeight = UpgradeCalicoHeight + (builtin2.EpochsInHour * 60)
 
+const UpgradeOrangeHeight = 336458
+
 // 2020-12-22T02:00:00Z
 const UpgradeClausHeight = 343200
 
diff --git a/chain/stmgr/forks.go b/chain/stmgr/forks.go
index 3bdf23f59..7fe12d2a8 100644
--- a/chain/stmgr/forks.go
+++ b/chain/stmgr/forks.go
@@ -96,6 +96,10 @@ func DefaultUpgradeSchedule() UpgradeSchedule {
 		Height:    build.UpgradePersianHeight,
 		Network:   network.Version8,
 		Migration: nil,
+	}, {
+		Height:    build.UpgradeOrangeHeight,
+		Network:   network.Version9,
+		Migration: nil,
 	}}
 
 	if build.UpgradeActorsV2Height == math.MaxInt64 { // disable actors upgrade