diff --git a/api/cbor_gen.go b/api/cbor_gen.go
index 7e1192037..8d309a6cc 100644
--- a/api/cbor_gen.go
+++ b/api/cbor_gen.go
@@ -9,7 +9,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/chain/actors/actor_miner.go b/chain/actors/actor_miner.go
index 3360f5e25..59ccf0b2a 100644
--- a/chain/actors/actor_miner.go
+++ b/chain/actors/actor_miner.go
@@ -264,6 +264,10 @@ func (sma StorageMinerActor) PreCommitSector(act *types.Actor, vmctx types.VMCon
 		ReceivedEpoch: vmctx.BlockHeight(),
 	}
 
+	if len(self.PreCommittedSectors) > 4096 {
+		return nil, aerrors.New(5, "too many precommitted sectors")
+	}
+
 	nstate, err := vmctx.Storage().Put(self)
 	if err != nil {
 		return nil, err
diff --git a/chain/actors/cbor_gen.go b/chain/actors/cbor_gen.go
index 83582a44b..0629d0b49 100644
--- a/chain/actors/cbor_gen.go
+++ b/chain/actors/cbor_gen.go
@@ -12,7 +12,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
@@ -204,6 +204,10 @@ func (t *StorageMinerActorState) MarshalCBOR(w io.Writer) error {
 
 	// t.PreCommittedSectors (map[string]*actors.PreCommittedSector) (map)
 	{
+		if len(t.PreCommittedSectors) > 4096 {
+			return xerrors.Errorf("cannot marshal t.PreCommittedSectors map too large")
+		}
+
 		if err := cbg.CborWriteHeader(w, cbg.MajMap, uint64(len(t.PreCommittedSectors))); err != nil {
 			return err
 		}
@@ -1979,6 +1983,10 @@ func (t *PaymentChannelActorState) MarshalCBOR(w io.Writer) error {
 
 	// t.LaneStates (map[string]*actors.LaneState) (map)
 	{
+		if len(t.LaneStates) > 4096 {
+			return xerrors.Errorf("cannot marshal t.LaneStates map too large")
+		}
+
 		if err := cbg.CborWriteHeader(w, cbg.MajMap, uint64(len(t.LaneStates))); err != nil {
 			return err
 		}
diff --git a/chain/blocksync/cbor_gen.go b/chain/blocksync/cbor_gen.go
index 8e2627cb7..341125bfd 100644
--- a/chain/blocksync/cbor_gen.go
+++ b/chain/blocksync/cbor_gen.go
@@ -10,7 +10,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/chain/deals/cbor_gen.go b/chain/deals/cbor_gen.go
index 5d175fc72..1251267f5 100644
--- a/chain/deals/cbor_gen.go
+++ b/chain/deals/cbor_gen.go
@@ -11,7 +11,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/chain/types/cbor_gen.go b/chain/types/cbor_gen.go
index 5bf2ffce8..57001aa16 100644
--- a/chain/types/cbor_gen.go
+++ b/chain/types/cbor_gen.go
@@ -10,7 +10,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/go.mod b/go.mod
index 942e2f284..9919fd624 100644
--- a/go.mod
+++ b/go.mod
@@ -87,7 +87,7 @@ require (
 	github.com/smartystreets/goconvey v0.0.0-20190731233626-505e41936337 // indirect
 	github.com/stretchr/testify v1.4.0
 	github.com/whyrusleeping/bencher v0.0.0-20190829221104-bb6607aa8bba
-	github.com/whyrusleeping/cbor-gen v0.0.0-20191209162422-1c55bd7cf8aa
+	github.com/whyrusleeping/cbor-gen v0.0.0-20191212224538-d370462a7e8a
 	github.com/whyrusleeping/multiaddr-filter v0.0.0-20160516205228-e903e4adabd7
 	github.com/whyrusleeping/pubsub v0.0.0-20131020042734-02de8aa2db3d
 	go.opencensus.io v0.22.1
diff --git a/go.sum b/go.sum
index 45d7afb48..dfe738c50 100644
--- a/go.sum
+++ b/go.sum
@@ -590,6 +590,8 @@ github.com/whyrusleeping/cbor-gen v0.0.0-20191116002219-891f55cd449d h1:NRa/Vs7+
 github.com/whyrusleeping/cbor-gen v0.0.0-20191116002219-891f55cd449d/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
 github.com/whyrusleeping/cbor-gen v0.0.0-20191209162422-1c55bd7cf8aa h1:iuIvC21JR4TcHtdCtkXz2jG8KCAK9ZJQQQxbDkFxkNE=
 github.com/whyrusleeping/cbor-gen v0.0.0-20191209162422-1c55bd7cf8aa/go.mod h1:xdlJQaiqipF0HW+Mzpg7XRM3fWbGvfgFlcppuvlkIvY=
+github.com/whyrusleeping/cbor-gen v0.0.0-20191212224538-d370462a7e8a h1:xc8sbWMwBsvi8OrxFZR8zxw/fdCneHBLFDJJaV14eaE=
+github.com/whyrusleeping/cbor-gen v0.0.0-20191212224538-d370462a7e8a/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=
diff --git a/paych/cbor_gen.go b/paych/cbor_gen.go
index b281bc755..abe1d135f 100644
--- a/paych/cbor_gen.go
+++ b/paych/cbor_gen.go
@@ -9,7 +9,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/retrieval/cbor_gen.go b/retrieval/cbor_gen.go
index f7a6279a9..3bf65c60e 100644
--- a/retrieval/cbor_gen.go
+++ b/retrieval/cbor_gen.go
@@ -8,7 +8,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf
 
diff --git a/storage/cbor_gen.go b/storage/cbor_gen.go
index 94a0bfb0d..43262ad2b 100644
--- a/storage/cbor_gen.go
+++ b/storage/cbor_gen.go
@@ -8,7 +8,7 @@ import (
 	xerrors "golang.org/x/xerrors"
 )
 
-/* This file was generated by github.com/whyrusleeping/cbor-gen */
+// Code generated by github.com/whyrusleeping/cbor-gen. DO NOT EDIT.
 
 var _ = xerrors.Errorf