diff --git a/build/params_2k.go b/build/params_2k.go
index 4c612d3ca..f822d701e 100644
--- a/build/params_2k.go
+++ b/build/params_2k.go
@@ -22,7 +22,7 @@ const GenesisFile = ""
 var NetworkBundle = "devnet"
 var BundleOverrides map[actorstypes.Version]string
 
-const GenesisNetworkVersion = network.Version16
+const GenesisNetworkVersion = network.Version18
 
 var UpgradeBreezeHeight = abi.ChainEpoch(-1)
 
@@ -56,7 +56,7 @@ var UpgradeOhSnapHeight = abi.ChainEpoch(-18)
 
 var UpgradeSkyrHeight = abi.ChainEpoch(-19)
 
-var UpgradeSharkHeight = abi.ChainEpoch(100)
+var UpgradeSharkHeight = abi.ChainEpoch(-20)
 
 var DrandSchedule = map[abi.ChainEpoch]DrandEnum{
 	0: DrandMainnet,