diff --git a/api/test/deals.go b/api/test/deals.go
index 0f90fa87c..695000b70 100644
--- a/api/test/deals.go
+++ b/api/test/deals.go
@@ -43,7 +43,7 @@ func TestDealFlow(t *testing.T, b APIBuilder, blocktime time.Duration) {
 	}
 	time.Sleep(time.Second)
 
-	data := make([]byte, 1600)
+	data := make([]byte, 600)
 	rand.New(rand.NewSource(5)).Read(data)
 
 	r := bytes.NewReader(data)
diff --git a/chain/gen/gen.go b/chain/gen/gen.go
index c14c62b7d..c48a924eb 100644
--- a/chain/gen/gen.go
+++ b/chain/gen/gen.go
@@ -36,8 +36,6 @@ import (
 	"github.com/filecoin-project/lotus/genesis"
 	"github.com/filecoin-project/lotus/lib/sigs"
 	"github.com/filecoin-project/lotus/node/repo"
-	"github.com/filecoin-project/lotus/storage/sectorstorage/mock"
-
 	"go.opencensus.io/trace"
 	"golang.org/x/xerrors"
 )
@@ -689,9 +687,6 @@ var _ sectorbuilder.Verifier = (*genFakeVerifier)(nil)
 func (m genFakeVerifier) VerifyElectionPost(ctx context.Context, pvi abi.PoStVerifyInfo) (bool, error) {
 	panic("nyi")
 }
-func (m genFakeVerifier) GenerateDataCommitment(ssize abi.PaddedPieceSize, pieces []abi.PieceInfo) (cid.Cid, error) {
-	return mock.MockVerifier.GenerateDataCommitment(ssize, pieces)
-}
 
 func (m genFakeVerifier) VerifySeal(svi abi.SealVerifyInfo) (bool, error) {
 	return true, nil
diff --git a/go.mod b/go.mod
index e9c35cb3e..c8bad4191 100644
--- a/go.mod
+++ b/go.mod
@@ -24,7 +24,7 @@ require (
 	github.com/filecoin-project/go-fil-markets v0.0.0-20200318012938-6403a5bda668
 	github.com/filecoin-project/go-padreader v0.0.0-20200210211231-548257017ca6
 	github.com/filecoin-project/go-paramfetch v0.0.2-0.20200218225740-47c639bab663
-	github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200317221918-42574fc2aab9
+	github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200325225948-053034f69825
 	github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9
 	github.com/filecoin-project/go-statestore v0.1.0
 	github.com/filecoin-project/specs-actors v0.0.0-20200321055844-54fa2e8da1c2
diff --git a/go.sum b/go.sum
index 78d4c8071..35a5154e7 100644
--- a/go.sum
+++ b/go.sum
@@ -127,8 +127,8 @@ github.com/filecoin-project/go-padreader v0.0.0-20200210211231-548257017ca6/go.m
 github.com/filecoin-project/go-paramfetch v0.0.2-0.20200218225740-47c639bab663 h1:eYxi6vI5CyeXD15X1bB3bledDXbqKxqf0wQzTLgwYwA=
 github.com/filecoin-project/go-paramfetch v0.0.2-0.20200218225740-47c639bab663/go.mod h1:fZzmf4tftbwf9S37XRifoJlz7nCjRdIrMGLR07dKLCc=
 github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200311224656-7d83652bdbed/go.mod h1:xAd/X905Ncgj8kkHsP2pmQUf6MQT2qJTDcOEfkwCjYc=
-github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200317221918-42574fc2aab9 h1:ROfxm5X9dMATYk6MvNe8WBcL2yaelpgGEvve5CnZ1+g=
-github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200317221918-42574fc2aab9/go.mod h1:3c3MEU9GHLlau37+MmefFNunTo9sVEKfjaJuHBgksdY=
+github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200325225948-053034f69825 h1:T+ghJLZsXXn7UYoYFXCmoVlGcVOJo7e5VgTP6EnGlpg=
+github.com/filecoin-project/go-sectorbuilder v0.0.2-0.20200325225948-053034f69825/go.mod h1:3c3MEU9GHLlau37+MmefFNunTo9sVEKfjaJuHBgksdY=
 github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9 h1:k9qVR9ItcziSB2rxtlkN/MDWNlbsI6yzec+zjUatLW0=
 github.com/filecoin-project/go-statemachine v0.0.0-20200226041606-2074af6d51d9/go.mod h1:FGwQgZAt2Gh5mjlwJUlVB62JeYdo+if0xWxSEfBD9ig=
 github.com/filecoin-project/go-statestore v0.1.0 h1:t56reH59843TwXHkMcwyuayStBIiWBRilQjQ+5IiwdQ=
diff --git a/storage/sectorstorage/mock/mock.go b/storage/sectorstorage/mock/mock.go
index fdaae7f80..ca50ed189 100644
--- a/storage/sectorstorage/mock/mock.go
+++ b/storage/sectorstorage/mock/mock.go
@@ -159,7 +159,7 @@ func (sb *SectorMgr) SealPreCommit1(ctx context.Context, sid abi.SectorID, ticke
 		}
 	}
 
-	commd, err := MockVerifier.GenerateDataCommitment(abi.PaddedPieceSize(sb.sectorSize), pis)
+	commd, err := MockVerifier.GenerateDataCommitment(sb.proofType, pis)
 	if err != nil {
 		return nil, err
 	}
@@ -354,15 +354,8 @@ func (m mockVerif) VerifySeal(svi abi.SealVerifyInfo) (bool, error) {
 	return true, nil
 }
 
-func (m mockVerif) GenerateDataCommitment(ssize abi.PaddedPieceSize, pieces []abi.PieceInfo) (cid.Cid, error) {
-	if len(pieces) != 1 {
-		panic("todo")
-	}
-	if pieces[0].Size != ssize {
-		fmt.Println("wrong sizes? ", pieces[0].Size, ssize)
-		panic("todo")
-	}
-	return pieces[0].PieceCID, nil
+func (m mockVerif) GenerateDataCommitment(pt abi.RegisteredProof, pieces []abi.PieceInfo) (cid.Cid, error) {
+	return sectorbuilder.GenerateUnsealedCID(pt, pieces)
 }
 
 var MockVerifier = mockVerif{}