diff --git a/chain/actors/builtin/miner/utils.go b/chain/actors/builtin/miner/utils.go
index 12164f9ee6e..cafc0f33418 100644
--- a/chain/actors/builtin/miner/utils.go
+++ b/chain/actors/builtin/miner/utils.go
@@ -8,6 +8,14 @@ import (
 	"github.com/filecoin-project/go-state-types/network"
 )
 
+type SealProofVariant int
+
+const (
+	SealProofVariant_Standard SealProofVariant = iota
+	SealProofVariant_Synthetic
+	SealProofVariant_NonInteractive
+)
+
 var MinSyntheticPoRepVersion = network.Version21
 var MinNonInteractivePoRepVersion = network.Version23
 
@@ -34,15 +42,16 @@ func AllPartSectors(mas State, sget func(Partition) (bitfield.BitField, error))
 
 // SealProofTypeFromSectorSize returns preferred seal proof type for creating
 // new miner actors and new sectors
-func SealProofTypeFromSectorSize(ssize abi.SectorSize, nv network.Version, synthetic bool, nonInteractive bool) (abi.RegisteredSealProof, error) {
-	if nv < MinSyntheticPoRepVersion && synthetic {
-		return 0, xerrors.Errorf("synthetic proofs are not supported on network version %d", nv)
-	}
-	if nv < MinNonInteractivePoRepVersion && nonInteractive {
-		return 0, xerrors.Errorf("non-interactive proofs are not supported on network version %d", nv)
-	}
-	if synthetic && nonInteractive {
-		return 0, xerrors.Errorf("synthetic and non-interactive proofs are mutually exclusive")
+func SealProofTypeFromSectorSize(ssize abi.SectorSize, nv network.Version, variant SealProofVariant) (abi.RegisteredSealProof, error) {
+	switch variant {
+	case SealProofVariant_Synthetic:
+		if nv < MinSyntheticPoRepVersion {
+			return 0, xerrors.Errorf("synthetic proofs are not supported on network version %d", nv)
+		}
+	case SealProofVariant_NonInteractive:
+		if nv < MinNonInteractivePoRepVersion {
+			return 0, xerrors.Errorf("non-interactive proofs are not supported on network version %d", nv)
+		}
 	}
 
 	switch {
@@ -78,10 +87,10 @@ func SealProofTypeFromSectorSize(ssize abi.SectorSize, nv network.Version, synth
 			return 0, xerrors.Errorf("unsupported sector size for miner: %v", ssize)
 		}
 
-		if synthetic {
+		switch variant {
+		case SealProofVariant_Synthetic:
 			return toSynthetic(v)
-		}
-		if nonInteractive {
+		case SealProofVariant_NonInteractive:
 			return toNonInteractive(v)
 		}
 		return v, nil
diff --git a/chain/gen/genesis/miners.go b/chain/gen/genesis/miners.go
index 52b4d4a890e..340ed75f1f6 100644
--- a/chain/gen/genesis/miners.go
+++ b/chain/gen/genesis/miners.go
@@ -138,7 +138,11 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sys vm.Syscal
 		i := i
 		m := m
 
-		spt, err := miner.SealProofTypeFromSectorSize(m.SectorSize, nv, synthetic)
+		variant := miner.SealProofVariant_Standard
+		if synthetic {
+			variant = miner.SealProofVariant_Synthetic
+		}
+		spt, err := miner.SealProofTypeFromSectorSize(m.SectorSize, nv, variant)
 		if err != nil {
 			return cid.Undef, err
 		}
diff --git a/cmd/lotus-bench/main.go b/cmd/lotus-bench/main.go
index da95f53b9dd..8c415180612 100644
--- a/cmd/lotus-bench/main.go
+++ b/cmd/lotus-bench/main.go
@@ -338,7 +338,7 @@ var sealBenchCmd = &cli.Command{
 
 		if !skipc2 {
 			log.Info("generating winning post candidates")
-			wipt, err := spt(sectorSize, false, false).RegisteredWinningPoStProof()
+			wipt, err := spt(sectorSize, miner.SealProofVariant_Standard).RegisteredWinningPoStProof()
 			if err != nil {
 				return err
 			}
@@ -556,7 +556,7 @@ func runSeals(sb *ffiwrapper.Sealer, sbfs *basicfs.Provider, numSectors int, par
 				Miner:  mid,
 				Number: i,
 			},
-			ProofType: spt(sectorSize, false, false),
+			ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 		}
 
 		start := time.Now()
@@ -586,7 +586,7 @@ func runSeals(sb *ffiwrapper.Sealer, sbfs *basicfs.Provider, numSectors int, par
 							Miner:  mid,
 							Number: i,
 						},
-						ProofType: spt(sectorSize, false, false),
+						ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 					}
 
 					start := time.Now()
@@ -797,7 +797,7 @@ var proveCmd = &cli.Command{
 				Miner:  abi.ActorID(mid),
 				Number: abi.SectorNumber(c2in.SectorNum),
 			},
-			ProofType: spt(abi.SectorSize(c2in.SectorSize), false, false),
+			ProofType: spt(abi.SectorSize(c2in.SectorSize), miner.SealProofVariant_Standard),
 		}
 
 		fmt.Printf("----\nstart proof computation\n")
@@ -828,8 +828,8 @@ func bps(sectorSize abi.SectorSize, sectorNum int, d time.Duration) string {
 	return types.SizeStr(types.BigInt{Int: bps}) + "/s"
 }
 
-func spt(ssize abi.SectorSize, synth bool, ni bool) abi.RegisteredSealProof {
-	spt, err := miner.SealProofTypeFromSectorSize(ssize, build.TestNetworkVersion, synth, ni)
+func spt(ssize abi.SectorSize, variant miner.SealProofVariant) abi.RegisteredSealProof {
+	spt, err := miner.SealProofTypeFromSectorSize(ssize, build.TestNetworkVersion, variant)
 	if err != nil {
 		panic(err)
 	}
diff --git a/cmd/lotus-bench/simple.go b/cmd/lotus-bench/simple.go
index b771bc3c650..4c32d366a2e 100644
--- a/cmd/lotus-bench/simple.go
+++ b/cmd/lotus-bench/simple.go
@@ -21,6 +21,7 @@ import (
 	prf "github.com/filecoin-project/specs-actors/actors/runtime/proof"
 
 	"github.com/filecoin-project/lotus/build"
+	"github.com/filecoin-project/lotus/chain/actors/builtin/miner"
 	lcli "github.com/filecoin-project/lotus/cli"
 	"github.com/filecoin-project/lotus/storage/sealer/ffiwrapper"
 	"github.com/filecoin-project/lotus/storage/sealer/storiface"
@@ -186,7 +187,7 @@ var simpleAddPiece = &cli.Command{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, false, false),
+			ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 		}
 
 		data, err := os.Open(cctx.Args().First())
@@ -262,12 +263,17 @@ var simplePreCommit1 = &cli.Command{
 			return err
 		}
 
+		variant, err := variantFromArgs(cctx)
+		if err != nil {
+			return err
+		}
+
 		sr := storiface.SectorRef{
 			ID: abi.SectorID{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, cctx.Bool("synthetic"), cctx.Bool("non-interactive")),
+			ProofType: spt(sectorSize, variant),
 		}
 
 		ticket := [32]byte{}
@@ -391,12 +397,17 @@ Example invocation of lotus-bench as external executor:
 			return err
 		}
 
+		variant, err := variantFromArgs(cctx)
+		if err != nil {
+			return err
+		}
+
 		sr := storiface.SectorRef{
 			ID: abi.SectorID{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, cctx.Bool("synthetic"), cctx.Bool("non-interactive")),
+			ProofType: spt(sectorSize, variant),
 		}
 
 		start := time.Now()
@@ -465,12 +476,17 @@ var simpleCommit1 = &cli.Command{
 			return err
 		}
 
+		variant, err := variantFromArgs(cctx)
+		if err != nil {
+			return err
+		}
+
 		sr := storiface.SectorRef{
 			ID: abi.SectorID{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, cctx.Bool("synthetic"), cctx.Bool("non-interactive")),
+			ProofType: spt(sectorSize, variant),
 		}
 
 		start := time.Now()
@@ -590,12 +606,17 @@ var simpleCommit2 = &cli.Command{
 			return err
 		}
 
+		variant, err := variantFromArgs(c)
+		if err != nil {
+			return err
+		}
+
 		ref := storiface.SectorRef{
 			ID: abi.SectorID{
 				Miner:  abi.ActorID(mid),
 				Number: abi.SectorNumber(c2in.SectorNum),
 			},
-			ProofType: spt(abi.SectorSize(c2in.SectorSize), c.Bool("synthetic"), c.Bool("non-interactive")),
+			ProofType: spt(abi.SectorSize(c2in.SectorSize), variant),
 		}
 
 		start := time.Now()
@@ -653,7 +674,7 @@ var simpleWindowPost = &cli.Command{
 			return xerrors.Errorf("parse commr: %w", err)
 		}
 
-		wpt, err := spt(sectorSize, false, false).RegisteredWindowPoStProof()
+		wpt, err := spt(sectorSize, miner.SealProofVariant_Standard).RegisteredWindowPoStProof()
 		if err != nil {
 			return err
 		}
@@ -673,7 +694,7 @@ var simpleWindowPost = &cli.Command{
 
 		vp, err := ffi.GenerateSingleVanillaProof(ffi.PrivateSectorInfo{
 			SectorInfo: prf.SectorInfo{
-				SealProof:    spt(sectorSize, false, false),
+				SealProof:    spt(sectorSize, miner.SealProofVariant_Standard),
 				SectorNumber: sn,
 				SealedCID:    commr,
 			},
@@ -744,7 +765,7 @@ var simpleWinningPost = &cli.Command{
 			return xerrors.Errorf("parse commr: %w", err)
 		}
 
-		wpt, err := spt(sectorSize, false, false).RegisteredWinningPoStProof()
+		wpt, err := spt(sectorSize, miner.SealProofVariant_Standard).RegisteredWinningPoStProof()
 		if err != nil {
 			return err
 		}
@@ -764,7 +785,7 @@ var simpleWinningPost = &cli.Command{
 
 		vp, err := ffi.GenerateSingleVanillaProof(ffi.PrivateSectorInfo{
 			SectorInfo: prf.SectorInfo{
-				SealProof:    spt(sectorSize, false, false),
+				SealProof:    spt(sectorSize, miner.SealProofVariant_Standard),
 				SectorNumber: sn,
 				SealedCID:    commr,
 			},
@@ -858,7 +879,7 @@ var simpleReplicaUpdate = &cli.Command{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, false, false),
+			ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 		}
 
 		start := time.Now()
@@ -926,7 +947,7 @@ var simpleProveReplicaUpdate1 = &cli.Command{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, false, false),
+			ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 		}
 
 		start := time.Now()
@@ -1013,7 +1034,7 @@ var simpleProveReplicaUpdate2 = &cli.Command{
 				Miner:  mid,
 				Number: 1,
 			},
-			ProofType: spt(sectorSize, false, false),
+			ProofType: spt(sectorSize, miner.SealProofVariant_Standard),
 		}
 
 		start := time.Now()
@@ -1087,3 +1108,16 @@ func ParsePieceInfos(cctx *cli.Context, firstArg int) ([]abi.PieceInfo, error) {
 
 	return out, nil
 }
+
+func variantFromArgs(cctx *cli.Context) (miner.SealProofVariant, error) {
+	variant := miner.SealProofVariant_Standard
+	if cctx.Bool("synthetic") {
+		if cctx.Bool("non-interactive") {
+			return variant, xerrors.Errorf("can't use both synthetic and non-interactive")
+		}
+		variant = miner.SealProofVariant_Synthetic
+	} else if cctx.Bool("non-interactive") {
+		variant = miner.SealProofVariant_NonInteractive
+	}
+	return variant, nil
+}
diff --git a/cmd/lotus-seed/main.go b/cmd/lotus-seed/main.go
index dd70cce2177..1a9a3ce2499 100644
--- a/cmd/lotus-seed/main.go
+++ b/cmd/lotus-seed/main.go
@@ -137,9 +137,8 @@ var preSealCmd = &cli.Command{
 			nv = network.Version(c.Uint64("network-version"))
 		}
 
-		var synthetic = false // there's little reason to have this for a seed.
-
-		spt, err := miner.SealProofTypeFromSectorSize(sectorSize, nv, synthetic)
+		var variant = miner.SealProofVariant_Standard // there's little reason to have this for a seed.
+		spt, err := miner.SealProofTypeFromSectorSize(sectorSize, nv, variant)
 		if err != nil {
 			return err
 		}
diff --git a/itests/kit/ensemble.go b/itests/kit/ensemble.go
index bc4d50fee01..5f8f60ccd35 100644
--- a/itests/kit/ensemble.go
+++ b/itests/kit/ensemble.go
@@ -260,7 +260,7 @@ func (n *Ensemble) MinerEnroll(minerNode *TestMiner, full *TestFullNode, opts ..
 		)
 
 		// Will use 2KiB sectors by default (default value of sectorSize).
-		proofType, err := miner.SealProofTypeFromSectorSize(options.sectorSize, n.genesis.version, false)
+		proofType, err := miner.SealProofTypeFromSectorSize(options.sectorSize, n.genesis.version, miner.SealProofVariant_Standard)
 		require.NoError(n.t, err)
 
 		// Create the preseal commitment.
diff --git a/itests/kit/node_opts.go b/itests/kit/node_opts.go
index 89c04b1c766..3d2b16e4e70 100644
--- a/itests/kit/node_opts.go
+++ b/itests/kit/node_opts.go
@@ -25,6 +25,7 @@ import (
 const DefaultPresealsPerBootstrapMiner = 2
 
 const TestSpt = abi.RegisteredSealProof_StackedDrg2KiBV1_1
+const TestSptNi = abi.RegisteredSealProof_StackedDrg2KiBV1_2_Feat_NiPoRep
 
 // nodeOpts is an options accumulating struct, where functional options are
 // merged into.
diff --git a/itests/migration_test.go b/itests/migration_test.go
index e19aaf45f74..c0c61d010d2 100644
--- a/itests/migration_test.go
+++ b/itests/migration_test.go
@@ -302,7 +302,7 @@ func TestMigrationNV17(t *testing.T) {
 	minerInfo, err := testClient.StateMinerInfo(ctx, testMiner.ActorAddr, types.EmptyTSK)
 	require.NoError(t, err)
 
-	spt, err := miner.SealProofTypeFromSectorSize(minerInfo.SectorSize, network.Version17, false)
+	spt, err := miner.SealProofTypeFromSectorSize(minerInfo.SectorSize, network.Version17, miner.SealProofVariant_Standard)
 	require.NoError(t, err)
 
 	preCommitParams := miner9.PreCommitSectorParams{