diff --git a/chain/actors/actor_init.go b/chain/actors/actor_init.go
index acb5cfd00..dddcb63cd 100644
--- a/chain/actors/actor_init.go
+++ b/chain/actors/actor_init.go
@@ -5,9 +5,11 @@ import (
 	"context"
 	"encoding/binary"
 	"fmt"
+
 	"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
 	"github.com/filecoin-project/go-lotus/chain/address"
 	"github.com/filecoin-project/go-lotus/chain/types"
+	cbg "github.com/whyrusleeping/cbor-gen"
 	"golang.org/x/xerrors"
 
 	"github.com/ipfs/go-cid"
@@ -26,8 +28,6 @@ const (
 )
 
 func init() {
-	cbor.RegisterCborType(ExecParams{})
-	cbor.RegisterCborType(struct{}{})
 
 	n, err := cbor.WrapObject(map[string]string{}, mh.SHA2_256, -1)
 	if err != nil {
@@ -64,17 +64,16 @@ type ExecParams struct {
 	Params []byte
 }
 
-func CreateExecParams(act cid.Cid, obj interface{}) ([]byte, aerrors.ActorError) {
+func CreateExecParams(act cid.Cid, obj cbg.CBORMarshaler) ([]byte, aerrors.ActorError) {
 	encparams, err := SerializeParams(obj)
 	if err != nil {
 		return nil, aerrors.Wrap(err, "creating ExecParams")
 	}
 
-	var ep ExecParams
-	ep.Code = act
-	ep.Params = encparams
-
-	return SerializeParams(ep)
+	return SerializeParams(&ExecParams{
+		Code:   act,
+		Params: encparams,
+	})
 }
 
 func (ia InitActor) Exec(act *types.Actor, vmctx types.VMContext, p *ExecParams) ([]byte, aerrors.ActorError) {
@@ -117,10 +116,12 @@ func (ia InitActor) Exec(act *types.Actor, vmctx types.VMContext, p *ExecParams)
 		Head:    EmptyCBOR,
 		Nonce:   0,
 	}
-	_, err = vmctx.Storage().Put(struct{}{})
-	if err != nil {
-		return nil, err
-	}
+	/*
+		_, err = vmctx.Storage().Put(struct{}{})
+		if err != nil {
+			return nil, err
+		}
+	*/
 
 	// The call to the actors constructor will set up the initial state
 	// from the given parameters, setting `actor.Head` to a new value when successful.
@@ -153,7 +154,7 @@ func (ia InitActor) Exec(act *types.Actor, vmctx types.VMContext, p *ExecParams)
 		return nil, err
 	}
 
-	c, err := vmctx.Storage().Put(self)
+	c, err := vmctx.Storage().Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -213,7 +214,7 @@ func (ias *InitActorState) Lookup(cst *hamt.CborIpldStore, addr address.Address)
 	var val interface{}
 	err = amap.Find(context.TODO(), string(addr.Bytes()), &val)
 	if err != nil {
-		return address.Undef, xerrors.Errorf("ias lookup failed to do lookup: %w", err)
+		return address.Undef, xerrors.Errorf("ias lookup failed to do find: %w", err)
 	}
 
 	ival, ok := val.(uint64)
diff --git a/chain/actors/actor_miner.go b/chain/actors/actor_miner.go
index 0692c169b..bde5b815d 100644
--- a/chain/actors/actor_miner.go
+++ b/chain/actors/actor_miner.go
@@ -2,6 +2,7 @@ package actors
 
 import (
 	"context"
+
 	"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
 	"github.com/filecoin-project/go-lotus/chain/address"
 	"github.com/filecoin-project/go-lotus/chain/types"
@@ -14,18 +15,6 @@ import (
 	"golang.org/x/xerrors"
 )
 
-func init() {
-	cbor.RegisterCborType(StorageMinerActorState{})
-	cbor.RegisterCborType(StorageMinerConstructorParams{})
-	cbor.RegisterCborType(CommitSectorParams{})
-	cbor.RegisterCborType(MinerInfo{})
-	cbor.RegisterCborType(SubmitPoStParams{})
-	cbor.RegisterCborType(PieceInclVoucherData{})
-	cbor.RegisterCborType(InclusionProof{})
-	cbor.RegisterCborType(PaymentVerifyParams{})
-	cbor.RegisterCborType(UpdatePeerIDParams{})
-}
-
 var ProvingPeriodDuration = uint64(2 * 60) // an hour, for now
 const POST_SECTORS_COUNT = 8192
 
@@ -190,7 +179,7 @@ func (sma StorageMinerActor) StorageMinerConstructor(act *types.Actor, vmctx typ
 	self.Info = minfocid
 
 	storage := vmctx.Storage()
-	c, err := storage.Put(self)
+	c, err := storage.Put(&self)
 	if err != nil {
 		return nil, err
 	}
diff --git a/chain/actors/actor_multisig.go b/chain/actors/actor_multisig.go
index 68a35ae2b..f06da0e51 100644
--- a/chain/actors/actor_multisig.go
+++ b/chain/actors/actor_multisig.go
@@ -2,24 +2,13 @@ package actors
 
 import (
 	"github.com/ipfs/go-cid"
-	cbor "github.com/ipfs/go-ipld-cbor"
 
 	"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
 	"github.com/filecoin-project/go-lotus/chain/address"
 	"github.com/filecoin-project/go-lotus/chain/types"
-)
 
-func init() {
-	cbor.RegisterCborType(MultiSigActorState{})
-	cbor.RegisterCborType(MultiSigConstructorParams{})
-	cbor.RegisterCborType(MultiSigProposeParams{})
-	cbor.RegisterCborType(MultiSigTxID{})
-	cbor.RegisterCborType(MultiSigSwapSignerParams{})
-	cbor.RegisterCborType(MultiSigChangeReqParams{})
-	cbor.RegisterCborType(MTransaction{})
-	cbor.RegisterCborType(MultiSigRemoveSignerParam{})
-	cbor.RegisterCborType(MultiSigAddSignerParam{})
-}
+	cbg "github.com/whyrusleeping/cbor-gen"
+)
 
 type MultiSigActor struct{}
 type MultiSigActorState struct {
@@ -203,7 +192,9 @@ func (msa MultiSigActor) Propose(act *types.Actor, vmctx types.VMContext,
 		return nil, aerrors.Wrap(err, "saving state")
 	}
 
-	return SerializeParams(tx.TxID)
+	// REVIEW: On one hand, I like being very explicit about how we're doing the serialization
+	// on the other, maybe we shouldnt do direct calls to underlying serialization libs?
+	return cbg.CborEncodeMajorType(cbg.MajUnsignedInt, tx.TxID), nil
 }
 
 type MultiSigTxID struct {
diff --git a/chain/actors/actor_paych.go b/chain/actors/actor_paych.go
index 752c69ff4..107cf9efc 100644
--- a/chain/actors/actor_paych.go
+++ b/chain/actors/actor_paych.go
@@ -5,7 +5,6 @@ import (
 	"fmt"
 
 	"github.com/ipfs/go-cid"
-	cbor "github.com/ipfs/go-ipld-cbor"
 
 	"github.com/filecoin-project/go-lotus/build"
 	"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
@@ -13,14 +12,6 @@ import (
 	"github.com/filecoin-project/go-lotus/chain/types"
 )
 
-func init() {
-	cbor.RegisterCborType(PaymentChannelActorState{})
-	cbor.RegisterCborType(PCAConstructorParams{})
-	cbor.RegisterCborType(LaneState{})
-	cbor.RegisterCborType(PCAUpdateChannelStateParams{})
-	cbor.RegisterCborType(PaymentInfo{})
-}
-
 type PaymentChannelActor struct{}
 
 type PaymentInfo struct {
@@ -84,7 +75,7 @@ func (pca PaymentChannelActor) Constructor(act *types.Actor, vmctx types.VMConte
 	self.LaneStates = make(map[string]*LaneState)
 
 	storage := vmctx.Storage()
-	c, err := storage.Put(self)
+	c, err := storage.Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -136,7 +127,7 @@ func (pca PaymentChannelActor) UpdateChannelState(act *types.Actor, vmctx types.
 	}
 
 	if sv.Extra != nil {
-		encoded, err := SerializeParams(PaymentVerifyParams{sv.Extra.Data, params.Proof})
+		encoded, err := SerializeParams(&PaymentVerifyParams{sv.Extra.Data, params.Proof})
 		if err != nil {
 			return nil, err
 		}
@@ -203,7 +194,7 @@ func (pca PaymentChannelActor) UpdateChannelState(act *types.Actor, vmctx types.
 		}
 	}
 
-	ncid, err := storage.Put(self)
+	ncid, err := storage.Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -235,7 +226,7 @@ func (pca PaymentChannelActor) Close(act *types.Actor, vmctx types.VMContext, pa
 		self.ClosingAt = self.MinCloseHeight
 	}
 
-	ncid, err := storage.Put(self)
+	ncid, err := storage.Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -272,7 +263,7 @@ func (pca PaymentChannelActor) Collect(act *types.Actor, vmctx types.VMContext,
 
 	self.ToSend = types.NewInt(0)
 
-	ncid, err := storage.Put(self)
+	ncid, err := storage.Put(&self)
 	if err != nil {
 		return nil, err
 	}
diff --git a/chain/actors/actor_storagemarket.go b/chain/actors/actor_storagemarket.go
index 29bfeecce..47fa48223 100644
--- a/chain/actors/actor_storagemarket.go
+++ b/chain/actors/actor_storagemarket.go
@@ -10,18 +10,10 @@ import (
 
 	cid "github.com/ipfs/go-cid"
 	hamt "github.com/ipfs/go-hamt-ipld"
-	cbor "github.com/ipfs/go-ipld-cbor"
 	"github.com/libp2p/go-libp2p-core/peer"
+	cbg "github.com/whyrusleeping/cbor-gen"
 )
 
-func init() {
-	cbor.RegisterCborType(StorageMarketState{})
-	cbor.RegisterCborType(CreateStorageMinerParams{})
-	cbor.RegisterCborType(IsMinerParam{})
-	cbor.RegisterCborType(PowerLookupParams{})
-	cbor.RegisterCborType(UpdateStorageParams{})
-}
-
 type StorageMarketActor struct{}
 
 type smaMethods struct {
@@ -98,7 +90,7 @@ func (sma StorageMarketActor) CreateStorageMiner(act *types.Actor, vmctx types.V
 	}
 	self.Miners = ncid
 
-	nroot, err := vmctx.Storage().Put(self)
+	nroot, err := vmctx.Storage().Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -139,7 +131,7 @@ func (sma StorageMarketActor) UpdateStorage(act *types.Actor, vmctx types.VMCont
 
 	self.TotalStorage = types.BigAdd(self.TotalStorage, params.Delta)
 
-	nroot, err := vmctx.Storage().Put(self)
+	nroot, err := vmctx.Storage().Put(&self)
 	if err != nil {
 		return nil, err
 	}
@@ -179,7 +171,7 @@ func (sma StorageMarketActor) PowerLookup(act *types.Actor, vmctx types.VMContex
 		return nil, aerrors.New(1, "miner not registered with storage market")
 	}
 
-	ret, err := vmctx.Send(params.Miner, MAMethods.GetPower, types.NewInt(0), EmptyStructCBOR)
+	ret, err := vmctx.Send(params.Miner, MAMethods.GetPower, types.NewInt(0), nil)
 	if err != nil {
 		return nil, aerrors.Wrap(err, "invoke Miner.GetPower")
 	}
@@ -202,11 +194,7 @@ func (sma StorageMarketActor) IsMiner(act *types.Actor, vmctx types.VMContext, p
 		return nil, err
 	}
 
-	out, err := SerializeParams(has)
-	if err != nil {
-		return nil, err
-	}
-	return out, nil
+	return cbg.EncodeBool(has), nil
 }
 
 func MinerSetHas(ctx context.Context, vmctx types.VMContext, rcid cid.Cid, maddr address.Address) (bool, aerrors.ActorError) {
@@ -215,7 +203,7 @@ func MinerSetHas(ctx context.Context, vmctx types.VMContext, rcid cid.Cid, maddr
 		return false, aerrors.Escalate(err, "failed to load miner set")
 	}
 
-	_, err = nd.Find(context.TODO(), string(maddr.Bytes()))
+	err = nd.Find(context.TODO(), string(maddr.Bytes()), nil)
 	switch err {
 	case hamt.ErrNotFound:
 		return false, nil
diff --git a/chain/actors/actors.go b/chain/actors/actors.go
index 9efa5c873..1fc9c15ce 100644
--- a/chain/actors/actors.go
+++ b/chain/actors/actors.go
@@ -4,15 +4,9 @@ import (
 	"github.com/filecoin-project/go-lotus/chain/address"
 
 	"github.com/ipfs/go-cid"
-	cbor "github.com/ipfs/go-ipld-cbor"
 	mh "github.com/multiformats/go-multihash"
 )
 
-func init() {
-	cbor.RegisterCborType(InitActorState{})
-	cbor.RegisterCborType(AccountActorState{})
-}
-
 var AccountActorCodeCid cid.Cid
 var StorageMarketActorCodeCid cid.Cid
 var StorageMinerCodeCid cid.Cid
diff --git a/chain/actors/cbor_gen.go b/chain/actors/cbor_gen.go
index ad934a395..52217948f 100644
--- a/chain/actors/cbor_gen.go
+++ b/chain/actors/cbor_gen.go
@@ -39,7 +39,7 @@ func (t *InitActorState) UnmarshalCBOR(br io.Reader) error {
 		return err
 	}
 	if maj != cbg.MajArray {
-		return fmt.Errorf("cbor input should be of type array")
+		return fmt.Errorf("cbor input should be of type array (got %d, %d)", maj, extra)
 	}
 
 	if extra != 2 {
@@ -2007,7 +2007,7 @@ func (t *PaymentInfo) UnmarshalCBOR(br io.Reader) error {
 		return fmt.Errorf("expected cbor array")
 	}
 	if extra > 0 {
-		t.Vouchers = make([]types.SignedVoucher, extra)
+		t.Vouchers = make([]*types.SignedVoucher, extra)
 	}
 	for i := 0; i < int(extra); i++ {
 		var v types.SignedVoucher
@@ -2015,7 +2015,7 @@ func (t *PaymentInfo) UnmarshalCBOR(br io.Reader) error {
 			return err
 		}
 
-		t.Vouchers[i] = v
+		t.Vouchers[i] = &v
 	}
 
 	return nil
diff --git a/chain/actors/params.go b/chain/actors/params.go
index b899e10c0..94624502c 100644
--- a/chain/actors/params.go
+++ b/chain/actors/params.go
@@ -1,19 +1,21 @@
 package actors
 
 import (
+	"bytes"
+
 	"github.com/filecoin-project/go-lotus/chain/actors/aerrors"
-	cbor "github.com/ipfs/go-ipld-cbor"
+	cbg "github.com/whyrusleeping/cbor-gen"
 )
 
 var (
 	EmptyStructCBOR = []byte{0xa0}
 )
 
-func SerializeParams(i interface{}) ([]byte, aerrors.ActorError) {
-	dump, err := cbor.DumpObject(i)
-	if err != nil {
+func SerializeParams(i cbg.CBORMarshaler) ([]byte, aerrors.ActorError) {
+	buf := new(bytes.Buffer)
+	if err := i.MarshalCBOR(buf); err != nil {
 		// TODO: shouldnt this be a fatal error?
 		return nil, aerrors.Absorb(err, 1, "failed to encode parameter")
 	}
-	return dump, nil
+	return buf.Bytes(), nil
 }
diff --git a/chain/gen/utils.go b/chain/gen/utils.go
index 4b2faf7c9..dfe8f2d27 100644
--- a/chain/gen/utils.go
+++ b/chain/gen/utils.go
@@ -18,6 +18,7 @@ import (
 	hamt "github.com/ipfs/go-hamt-ipld"
 	bstore "github.com/ipfs/go-ipfs-blockstore"
 	peer "github.com/libp2p/go-libp2p-peer"
+	cbg "github.com/whyrusleeping/cbor-gen"
 	sharray "github.com/whyrusleeping/sharray"
 )
 
@@ -161,7 +162,7 @@ type GenMinerCfg struct {
 	PeerIDs []peer.ID
 }
 
-func mustEnc(i interface{}) []byte {
+func mustEnc(i cbg.CBORMarshaler) []byte {
 	enc, err := actors.SerializeParams(i)
 	if err != nil {
 		panic(err)
@@ -180,7 +181,7 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sroot cid.Cid
 		worker := gmcfg.Workers[i]
 		pid := gmcfg.PeerIDs[i]
 
-		params := mustEnc(actors.CreateStorageMinerParams{
+		params := mustEnc(&actors.CreateStorageMinerParams{
 			Owner:      owner,
 			Worker:     worker,
 			SectorSize: types.NewInt(build.SectorSize),
@@ -199,7 +200,7 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sroot cid.Cid
 
 		gmcfg.MinerAddrs = append(gmcfg.MinerAddrs, maddr)
 
-		params = mustEnc(actors.UpdateStorageParams{Delta: types.NewInt(5000)})
+		params = mustEnc(&actors.UpdateStorageParams{Delta: types.NewInt(5000)})
 
 		_, err = doExec(ctx, vm, actors.StorageMarketAddress, maddr, actors.SMAMethods.UpdateStorage, params)
 		if err != nil {
@@ -226,7 +227,7 @@ func SetupStorageMiners(ctx context.Context, cs *store.ChainStore, sroot cid.Cid
 		}
 		mstate.Power = types.NewInt(5000)
 
-		nstate, err := cst.Put(ctx, mstate)
+		nstate, err := cst.Put(ctx, &mstate)
 		if err != nil {
 			return cid.Undef, err
 		}
@@ -258,7 +259,7 @@ func doExec(ctx context.Context, vm *vm.VM, to, from address.Address, method uin
 		Nonce:    act.Nonce,
 	})
 	if err != nil {
-		return nil, err
+		return nil, xerrors.Errorf("doExec apply message failed: %w", err)
 	}
 
 	if ret.ExitCode != 0 {
diff --git a/chain/state/statetree.go b/chain/state/statetree.go
index ac5e15819..8b3df8e74 100644
--- a/chain/state/statetree.go
+++ b/chain/state/statetree.go
@@ -90,10 +90,10 @@ func (st *StateTree) GetActor(addr address.Address) (*types.Actor, error) {
 	if addr.Protocol() != address.ID {
 		iaddr, err := st.lookupID(addr)
 		if err != nil {
-			if err == hamt.ErrNotFound {
-				return nil, types.ErrActorNotFound
+			if xerrors.Is(err, hamt.ErrNotFound) {
+				return nil, xerrors.Errorf("lookup failed: %w", types.ErrActorNotFound)
 			}
-			return nil, err
+			return nil, xerrors.Errorf("address resolution: %w", err)
 		}
 		addr = iaddr
 	}
diff --git a/chain/stmgr/call.go b/chain/stmgr/call.go
index 9b04a094a..607273724 100644
--- a/chain/stmgr/call.go
+++ b/chain/stmgr/call.go
@@ -26,12 +26,6 @@ func (sm *StateManager) CallRaw(ctx context.Context, msg *types.Message, bstate
 	if msg.Value == types.EmptyInt {
 		msg.Value = types.NewInt(0)
 	}
-	if msg.Params == nil {
-		msg.Params, err = actors.SerializeParams(struct{}{})
-		if err != nil {
-			return nil, err
-		}
-	}
 
 	fromActor, err := vmi.StateTree().GetActor(msg.From)
 	if err != nil {
diff --git a/chain/stmgr/stmgr.go b/chain/stmgr/stmgr.go
index 76f94fa8a..447c1bd63 100644
--- a/chain/stmgr/stmgr.go
+++ b/chain/stmgr/stmgr.go
@@ -124,13 +124,13 @@ func (sm *StateManager) GetActor(addr address.Address) (*types.Actor, error) {
 	ts := sm.cs.GetHeaviestTipSet()
 	stcid, err := sm.TipSetState(ts.Cids())
 	if err != nil {
-		return nil, err
+		return nil, xerrors.Errorf("tipset state: %w", err)
 	}
 
 	cst := hamt.CSTFromBstore(sm.cs.Blockstore())
 	state, err := state.LoadStateTree(cst, stcid)
 	if err != nil {
-		return nil, err
+		return nil, xerrors.Errorf("load state tree: %w", err)
 	}
 
 	return state.GetActor(addr)
@@ -139,7 +139,7 @@ func (sm *StateManager) GetActor(addr address.Address) (*types.Actor, error) {
 func (sm *StateManager) GetBalance(addr address.Address) (types.BigInt, error) {
 	act, err := sm.GetActor(addr)
 	if err != nil {
-		return types.BigInt{}, err
+		return types.BigInt{}, xerrors.Errorf("get actor: %w", err)
 	}
 
 	return act.Balance, nil
diff --git a/chain/sync_test.go b/chain/sync_test.go
index 861c02237..4f35a7fd7 100644
--- a/chain/sync_test.go
+++ b/chain/sync_test.go
@@ -256,7 +256,7 @@ func (tu *syncTestUtil) submitSourceBlocks(to int, h int, n int) {
 */
 
 func TestSyncSimple(t *testing.T) {
-	H := 100
+	H := 15
 	tu := prepSyncTest(t, H)
 
 	client := tu.addClientNode()
diff --git a/chain/types/vmcontext.go b/chain/types/vmcontext.go
index b43492512..64507f69d 100644
--- a/chain/types/vmcontext.go
+++ b/chain/types/vmcontext.go
@@ -6,11 +6,12 @@ import (
 	"github.com/filecoin-project/go-lotus/chain/address"
 	"github.com/ipfs/go-cid"
 	"github.com/ipfs/go-hamt-ipld"
+	cbg "github.com/whyrusleeping/cbor-gen"
 )
 
 type Storage interface {
-	Put(interface{}) (cid.Cid, aerrors.ActorError)
-	Get(cid.Cid, interface{}) aerrors.ActorError
+	Put(cbg.CBORMarshaler) (cid.Cid, aerrors.ActorError)
+	Get(cid.Cid, cbg.CBORUnmarshaler) aerrors.ActorError
 
 	GetHead() cid.Cid
 
@@ -42,7 +43,7 @@ type storageWrapper struct {
 }
 
 func (sw *storageWrapper) Put(i interface{}) (cid.Cid, error) {
-	c, err := sw.s.Put(i)
+	c, err := sw.s.Put(i.(cbg.CBORMarshaler))
 	if err != nil {
 		return cid.Undef, err
 	}
@@ -51,7 +52,7 @@ func (sw *storageWrapper) Put(i interface{}) (cid.Cid, error) {
 }
 
 func (sw *storageWrapper) Get(c cid.Cid, out interface{}) error {
-	if err := sw.s.Get(c, out); err != nil {
+	if err := sw.s.Get(c, out.(cbg.CBORUnmarshaler)); err != nil {
 		return err
 	}
 
diff --git a/chain/vm/invoker.go b/chain/vm/invoker.go
index 4e7a035e3..7d9ff6b80 100644
--- a/chain/vm/invoker.go
+++ b/chain/vm/invoker.go
@@ -1,11 +1,13 @@
 package vm
 
 import (
+	"bytes"
 	"fmt"
 	"reflect"
 
 	"github.com/ipfs/go-cid"
 	cbor "github.com/ipfs/go-ipld-cbor"
+	cbg "github.com/whyrusleeping/cbor-gen"
 	"golang.org/x/xerrors"
 
 	actors "github.com/filecoin-project/go-lotus/chain/actors"
@@ -121,8 +123,7 @@ func (*invoker) transform(instance Invokee) (nativeCode, error) {
 
 				inBytes := in[2].Interface().([]byte)
 				if len(inBytes) > 0 {
-					err := cbor.DecodeInto(inBytes, param.Interface())
-					if err != nil {
+					if err := DecodeParams(inBytes, param.Interface()); err != nil {
 						aerr := aerrors.Absorb(err, 1, "failed to decode parameters")
 						return []reflect.Value{
 							reflect.ValueOf([]byte{}),
@@ -142,6 +143,15 @@ func (*invoker) transform(instance Invokee) (nativeCode, error) {
 	return code, nil
 }
 
+func DecodeParams(b []byte, out interface{}) error {
+	um, ok := out.(cbg.CBORUnmarshaler)
+	if !ok {
+		return fmt.Errorf("type %T does not implement UnmarshalCBOR", out)
+	}
+
+	return um.UnmarshalCBOR(bytes.NewReader(b))
+}
+
 func DumpActorState(code cid.Cid, b []byte) (interface{}, error) {
 	i := newInvoker() // TODO: register builtins in init block
 
diff --git a/chain/vm/vm.go b/chain/vm/vm.go
index c0ffbb4e2..82fc94094 100644
--- a/chain/vm/vm.go
+++ b/chain/vm/vm.go
@@ -11,6 +11,7 @@ import (
 	"github.com/filecoin-project/go-lotus/chain/store"
 	"github.com/filecoin-project/go-lotus/chain/types"
 	"github.com/filecoin-project/go-lotus/lib/bufbstore"
+	cbg "github.com/whyrusleeping/cbor-gen"
 	"go.opencensus.io/trace"
 
 	block "github.com/ipfs/go-block-format"
@@ -67,18 +68,19 @@ func (vmc *VMContext) Message() *types.Message {
 
 // Storage interface
 
-func (vmc *VMContext) Put(i interface{}) (cid.Cid, aerrors.ActorError) {
+func (vmc *VMContext) Put(i cbg.CBORMarshaler) (cid.Cid, aerrors.ActorError) {
 	c, err := vmc.cst.Put(context.TODO(), i)
 	if err != nil {
 		if aerr := vmc.ChargeGas(0); aerr != nil {
 			return cid.Undef, aerrors.Absorb(err, outOfGasErrCode, "Put out of gas")
 		}
-		return cid.Undef, aerrors.Escalate(err, "putting cid")
+		panic("no u")
+		return cid.Undef, aerrors.Escalate(err, fmt.Sprintf("putting object %T", i))
 	}
 	return c, nil
 }
 
-func (vmc *VMContext) Get(c cid.Cid, out interface{}) aerrors.ActorError {
+func (vmc *VMContext) Get(c cid.Cid, out cbg.CBORUnmarshaler) aerrors.ActorError {
 	err := vmc.cst.Get(context.TODO(), c, out)
 	if err != nil {
 		if aerr := vmc.ChargeGas(0); aerr != nil {
diff --git a/go.mod b/go.mod
index c9d39cca9..c4aa1f5af 100644
--- a/go.mod
+++ b/go.mod
@@ -22,7 +22,7 @@ require (
 	github.com/ipfs/go-ds-badger v0.0.5
 	github.com/ipfs/go-filestore v0.0.2
 	github.com/ipfs/go-fs-lock v0.0.1
-	github.com/ipfs/go-hamt-ipld v0.0.12-0.20190830015840-8aabc0c74ac6
+	github.com/ipfs/go-hamt-ipld v0.0.12-0.20190910032255-ee6e898f0456
 	github.com/ipfs/go-ipfs-blockstore v0.1.0
 	github.com/ipfs/go-ipfs-chunker v0.0.1
 	github.com/ipfs/go-ipfs-ds-help v0.0.1
@@ -67,7 +67,7 @@ require (
 	github.com/polydawn/refmt v0.0.0-20190809202753-05966cbd336a
 	github.com/stretchr/testify v1.4.0
 	github.com/whyrusleeping/bencher v0.0.0-20190829221104-bb6607aa8bba
-	github.com/whyrusleeping/cbor-gen v0.0.0-20190909233408-ae6265959798
+	github.com/whyrusleeping/cbor-gen v0.0.0-20190910040623-f29470053db6
 	github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7
 	github.com/whyrusleeping/pubsub v0.0.0-20131020042734-02de8aa2db3d
 	github.com/whyrusleeping/sharray v0.0.0-20190718051354-e41931821e33
diff --git a/go.sum b/go.sum
index 2d6d80ce3..f12c36d1a 100644
--- a/go.sum
+++ b/go.sum
@@ -170,6 +170,8 @@ github.com/ipfs/go-fs-lock v0.0.1 h1:XHX8uW4jQBYWHj59XXcjg7BHlHxV9ZOYs6Y43yb7/l0
 github.com/ipfs/go-fs-lock v0.0.1/go.mod h1:DNBekbboPKcxs1aukPSaOtFA3QfSdi5C855v0i9XJ8Y=
 github.com/ipfs/go-hamt-ipld v0.0.12-0.20190830015840-8aabc0c74ac6 h1:qVk+425ErvzJEz/9f38lhjPfmmu0GAj/BSNt56SW4xQ=
 github.com/ipfs/go-hamt-ipld v0.0.12-0.20190830015840-8aabc0c74ac6/go.mod h1:UPmViPxLn1GGxxnllIww8yWUVO60qEYLFFfF9e3ojgo=
+github.com/ipfs/go-hamt-ipld v0.0.12-0.20190910032255-ee6e898f0456 h1:I0DHyyygfm9fxWK3dZ6XAXBHVY2u93ske4kprAmm4og=
+github.com/ipfs/go-hamt-ipld v0.0.12-0.20190910032255-ee6e898f0456/go.mod h1:oVAOWGetjaaAPloFDCudyhxofsSG/WijXMJLTA0kRhM=
 github.com/ipfs/go-ipfs-blockstore v0.0.1/go.mod h1:d3WClOmRQKFnJ0Jz/jj/zmksX0ma1gROTlovZKBmN08=
 github.com/ipfs/go-ipfs-blockstore v0.0.2/go.mod h1:d3WClOmRQKFnJ0Jz/jj/zmksX0ma1gROTlovZKBmN08=
 github.com/ipfs/go-ipfs-blockstore v0.1.0 h1:V1GZorHFUIB6YgTJQdq7mcaIpUfCM3fCyVi+MTo9O88=
@@ -530,6 +532,10 @@ github.com/whyrusleeping/cbor-gen v0.0.0-20190909232404-de20c470a082 h1:Wh1Hyuaz
 github.com/whyrusleeping/cbor-gen v0.0.0-20190909232404-de20c470a082/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
 github.com/whyrusleeping/cbor-gen v0.0.0-20190909233408-ae6265959798 h1:4j/w+x60KmMsRwRavx3cxDgdV0iCRVoNCizhiAo2vF8=
 github.com/whyrusleeping/cbor-gen v0.0.0-20190909233408-ae6265959798/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
+github.com/whyrusleeping/cbor-gen v0.0.0-20190910031516-c1cbffdb01bb h1:8yBVx6dgk1GfkiWOQ+RbeDDBLCOZxOtmZ949O2uj5H4=
+github.com/whyrusleeping/cbor-gen v0.0.0-20190910031516-c1cbffdb01bb/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
+github.com/whyrusleeping/cbor-gen v0.0.0-20190910040623-f29470053db6 h1:e46mGjWNMelsw+YLq/5TyMfwGz8p0cBY2cf91y6tSBA=
+github.com/whyrusleeping/cbor-gen v0.0.0-20190910040623-f29470053db6/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
 github.com/whyrusleeping/chunker v0.0.0-20181014151217-fe64bd25879f h1:jQa4QT2UP9WYv2nzyawpKMOCl+Z/jW7djv2/J50lj9E=
 github.com/whyrusleeping/chunker v0.0.0-20181014151217-fe64bd25879f/go.mod h1:p9UJB6dDgdPgMJZs7UjUOdulKyRr9fqkS+6JKAInPy8=
 github.com/whyrusleeping/go-keyspace v0.0.0-20160322163242-5b898ac5add1 h1:EKhdznlJHPMoKr0XTrX+IlJs1LH3lyx2nfr1dOlZ79k=