diff --git a/chain/vm/runtime.go b/chain/vm/runtime.go
index 7c40fed62..2845c7696 100644
--- a/chain/vm/runtime.go
+++ b/chain/vm/runtime.go
@@ -229,7 +229,7 @@ func (rt *Runtime) GetRandomnessFromTickets(personalization crypto.DomainSeparat
 func (rt *Runtime) GetRandomnessFromBeacon(personalization crypto.DomainSeparationTag, randEpoch abi.ChainEpoch, entropy []byte) abi.Randomness {
 	var err error
 	var res []byte
-	if rt.vm.GetNtwkVersion(rt.ctx, randEpoch) >= network.Version13 {
+	if randEpoch > build.UpgradeHyperdriveHeight {
 		res, err = rt.vm.rand.GetBeaconRandomnessLookingForward(rt.ctx, personalization, randEpoch, entropy)
 	} else {
 		res, err = rt.vm.rand.GetBeaconRandomnessLookingBack(rt.ctx, personalization, randEpoch, entropy)