diff --git a/chain/stmgr/forks.go b/chain/stmgr/forks.go
index c1f48b8f6..f18e6824b 100644
--- a/chain/stmgr/forks.go
+++ b/chain/stmgr/forks.go
@@ -3,7 +3,12 @@ package stmgr
 import (
 	"context"
 
+	"github.com/filecoin-project/lotus/chain/types"
+
+	amt "github.com/filecoin-project/go-amt-ipld/v2"
 	"github.com/ipfs/go-cid"
+	cbg "github.com/whyrusleeping/cbor-gen"
+	"golang.org/x/xerrors"
 )
 
 func (sm *StateManager) handleStateForks(ctx context.Context, pstate cid.Cid, height, parentH uint64) (_ cid.Cid, err error) {
@@ -14,3 +19,31 @@ func (sm *StateManager) handleStateForks(ctx context.Context, pstate cid.Cid, he
 
 	return pstate, nil
 }
+
+func amtFsck(s types.Storage, ss cid.Cid) (cid.Cid, error) {
+	a, err := amt.LoadAMT(types.WrapStorage(s), ss)
+	if err != nil {
+		return cid.Undef, xerrors.Errorf("could not load AMT: %w", a)
+	}
+
+	b := amt.NewAMT(types.WrapStorage(s))
+
+	err = a.ForEach(func(id uint64, data *cbg.Deferred) error {
+		err := b.Set(id, data)
+		if err != nil {
+			return xerrors.Errorf("could not copy at idx (%d): %w", id, err)
+		}
+		return nil
+	})
+
+	if err != nil {
+		return cid.Undef, xerrors.Errorf("could not copy: %w", err)
+	}
+
+	nss, err := b.Flush()
+	if err != nil {
+		return cid.Undef, xerrors.Errorf("could not flush: %w", err)
+	}
+
+	return nss, nil
+}
diff --git a/go.mod b/go.mod
index 1daa92ac8..bd1c4c359 100644
--- a/go.mod
+++ b/go.mod
@@ -14,6 +14,7 @@ require (
 	github.com/filecoin-project/filecoin-ffi v0.0.0-20191219131535-bb699517a590
 	github.com/filecoin-project/go-address v0.0.0-20191219011437-af739c490b4f
 	github.com/filecoin-project/go-amt-ipld v0.0.0-20191205011053-79efc22d6cdc
+	github.com/filecoin-project/go-amt-ipld/v2 v2.0.0
 	github.com/filecoin-project/go-cbor-util v0.0.0-20191219014500-08c40a1e63a2
 	github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03
 	github.com/filecoin-project/go-data-transfer v0.0.0-20191219005021-4accf56bd2ce
diff --git a/go.sum b/go.sum
index 87bb230aa..d63fe2e69 100644
--- a/go.sum
+++ b/go.sum
@@ -104,10 +104,16 @@ github.com/filecoin-project/go-address v0.0.0-20191219011437-af739c490b4f h1:L2j
 github.com/filecoin-project/go-address v0.0.0-20191219011437-af739c490b4f/go.mod h1:rCbpXPva2NKF9/J4X6sr7hbKBgQCxyFtRj7KOZqoIms=
 github.com/filecoin-project/go-amt-ipld v0.0.0-20191205011053-79efc22d6cdc h1:cODZD2YzpTUtrOSxbEnWFcQHidNRZiRdvLxySjGvG/M=
 github.com/filecoin-project/go-amt-ipld v0.0.0-20191205011053-79efc22d6cdc/go.mod h1:KsFPWjF+UUYl6n9A+qbg4bjFgAOneicFZtDH/LQEX2U=
+github.com/filecoin-project/go-amt-ipld v1.0.0 h1:jJteqdKcwFYoN9Wgs7MzDWVWvRWUfhhFo4bltJ7wrus=
+github.com/filecoin-project/go-amt-ipld/v2 v2.0.0 h1:rQ7GTJbWE5XqUCPiBgs4gbTKD2wC7MynZhSaf7ZzlUM=
+github.com/filecoin-project/go-amt-ipld/v2 v2.0.0/go.mod h1:PAZ5tvSfMfWE327osqFXKm7cBpCpBk2Nh0qKsJUmjjk=
 github.com/filecoin-project/go-cbor-util v0.0.0-20191219014500-08c40a1e63a2 h1:av5fw6wmm58FYMgJeoB/lK9XXrgdugYiTqkdxjTy9k8=
 github.com/filecoin-project/go-cbor-util v0.0.0-20191219014500-08c40a1e63a2/go.mod h1:pqTiPHobNkOVM5thSRsHYjyQfq7O5QSCMhvuu9JoDlg=
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03 h1:2pMXdBnCiXjfCYx/hLqFxccPoqsSveQFxVLvNxy9bus=
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03 h1:2pMXdBnCiXjfCYx/hLqFxccPoqsSveQFxVLvNxy9bus=
+github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03 h1:2pMXdBnCiXjfCYx/hLqFxccPoqsSveQFxVLvNxy9bus=
+github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
+github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
 github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
 github.com/filecoin-project/go-data-transfer v0.0.0-20191219005021-4accf56bd2ce h1:Jdejrx6XVSTRy2PiX08HCU5y68p3wx2hNMJJc/J7kZY=
@@ -116,15 +122,12 @@ github.com/filecoin-project/go-fil-markets v0.0.0-20200114015428-74d100f305f8 h1
 github.com/filecoin-project/go-fil-markets v0.0.0-20200114015428-74d100f305f8/go.mod h1:c8NTjvFVy1Ud02mmGDjOiMeawY2t6ALfrrdvAB01FQc=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878 h1:YicJT9xhPzZ1SBGiJFNUCkfwqK/G9vFyY1ytKBSjNJA=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878 h1:YicJT9xhPzZ1SBGiJFNUCkfwqK/G9vFyY1ytKBSjNJA=
-github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
-github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
-github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03 h1:2pMXdBnCiXjfCYx/hLqFxccPoqsSveQFxVLvNxy9bus=
-github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
-github.com/filecoin-project/go-crypto v0.0.0-20191218222705-effae4ea9f03/go.mod h1:+viYnvGtUTgJRdy6oaeF4MTFKAfatX071MPDPBL11EQ=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878 h1:YicJT9xhPzZ1SBGiJFNUCkfwqK/G9vFyY1ytKBSjNJA=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878 h1:YicJT9xhPzZ1SBGiJFNUCkfwqK/G9vFyY1ytKBSjNJA=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
 github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
+github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
+github.com/filecoin-project/go-paramfetch v0.0.0-20200102181131-b20d579f2878/go.mod h1:40kI2Gv16mwcRsHptI3OAV4nlOEU7wVDc4RgMylNFjU=
 github.com/filecoin-project/go-paramfetch v0.0.1 h1:gV7bs5YaqlgpGFMiLxInGK2L1FyCXUE0rimz4L7ghoE=
 github.com/filecoin-project/go-paramfetch v0.0.1/go.mod h1:fZzmf4tftbwf9S37XRifoJlz7nCjRdIrMGLR07dKLCc=
 github.com/filecoin-project/go-sectorbuilder v0.0.1 h1:yiLSEprWA1E43DFTSCXLSuCstYuDKiI6RCXiYz4GaRs=