diff --git a/go.sum b/go.sum
index 63d7920e6..20f8f95fd 100644
--- a/go.sum
+++ b/go.sum
@@ -103,6 +103,7 @@ github.com/elastic/go-windows v1.0.0 h1:qLURgZFkkrYyTTkvYpsZIgf83AUsdIHfvlJaqaZ7
 github.com/elastic/go-windows v1.0.0/go.mod h1:TsU0Nrp7/y3+VwE82FoZF8gC/XFg/Elz6CcloAxnPgU=
 github.com/fatih/color v1.8.0 h1:5bzFgL+oy7JITMTxUPJ00n7VxmYd/PdMp5mHFX40/RY=
 github.com/fatih/color v1.8.0/go.mod h1:3l45GVGkyrnYNl9HoIjnp2NnNWvh6hLAqD8yTfGjnw8=
+github.com/filecoin-project/chain-validation v0.0.6-0.20200325210556-5a3014759d9c h1:I5xX6g6ySpRm9v6j3B5ML1OgeZDnAY/ppftDjdP6OMc=
 github.com/filecoin-project/chain-validation v0.0.6-0.20200325210556-5a3014759d9c/go.mod h1:mXiAviXMZ2WVGmWNtjGr0JPMpNCNsPU774DawKZCzzM=
 github.com/filecoin-project/go-address v0.0.0-20200107215422-da8eea2842b5/go.mod h1:SAOwJoakQ8EPjwNIsiakIQKsoKdkcbx8U3IapgCg9R0=
 github.com/filecoin-project/go-address v0.0.2-0.20200218010043-eb9bb40ed5be h1:TooKBwR/g8jG0hZ3lqe9S5sy2vTUcLOZLlz3M5wGn2E=
diff --git a/miner/miner.go b/miner/miner.go
index d4f02241e..0cf16e2ee 100644
--- a/miner/miner.go
+++ b/miner/miner.go
@@ -354,7 +354,7 @@ func (m *Miner) computeTicket(ctx context.Context, addr address.Address, base *M
 		return nil, xerrors.Errorf("failed to marshal address to cbor: %w", err)
 	}
 
-	input, err := m.api.ChainGetRandomness(ctx, base.ts.Key(), crypto.DomainSeparationTag_TicketProduction, base.ts.Height(), buf.Bytes())
+	input, err := m.api.ChainGetRandomness(ctx, base.ts.Key(), crypto.DomainSeparationTag_TicketProduction, (base.ts.Height()+base.nullRounds+1)-1, buf.Bytes())
 	if err != nil {
 		return nil, err
 	}