diff --git a/build/params.go b/build/params.go
index 75f49e74d..0c4908b74 100644
--- a/build/params.go
+++ b/build/params.go
@@ -123,3 +123,7 @@ func init() {
 
 // Sync
 const BadBlockCacheSize = 8192
+
+// assuming 4000 blocks per round, this lets us not lose any messages across a
+// 10 block reorg. 
+const BlsSignatureCacheSize = 40000
diff --git a/chain/messagepool.go b/chain/messagepool.go
index 5bb24f27f..63aa1bedb 100644
--- a/chain/messagepool.go
+++ b/chain/messagepool.go
@@ -4,10 +4,12 @@ import (
 	"fmt"
 	"sync"
 
+	lru "github.com/hashicorp/golang-lru"
 	pubsub "github.com/libp2p/go-libp2p-pubsub"
 	"github.com/pkg/errors"
 	"golang.org/x/xerrors"
 
+	"github.com/filecoin-project/lotus/build"
 	"github.com/filecoin-project/lotus/chain/address"
 	"github.com/filecoin-project/lotus/chain/stmgr"
 	"github.com/filecoin-project/lotus/chain/types"
@@ -38,6 +40,8 @@ type MessagePool struct {
 	minGasPrice types.BigInt
 
 	maxTxPoolSize int
+
+	blsSigCache *lru.TwoQueueCache
 }
 
 type msgSet struct {
@@ -68,12 +72,14 @@ func (ms *msgSet) add(m *types.SignedMessage) error {
 }
 
 func NewMessagePool(sm *stmgr.StateManager, ps *pubsub.PubSub) *MessagePool {
+	cache, _ := lru.New2Q(build.BlsSignatureCacheSize)
 	mp := &MessagePool{
 		pending:       make(map[address.Address]*msgSet),
 		sm:            sm,
 		ps:            ps,
 		minGasPrice:   types.NewInt(0),
 		maxTxPoolSize: 100000,
+		blsSigCache:   cache,
 	}
 	sm.ChainStore().SubscribeHeadChanges(mp.HeadChange)
 
@@ -138,6 +144,9 @@ func (mp *MessagePool) Add(m *types.SignedMessage) error {
 
 func (mp *MessagePool) addLocked(m *types.SignedMessage) error {
 	log.Debugf("mpooladd: %s %s", m.Message.From, m.Message.Nonce)
+	if m.Signature.Type == types.KTBLS {
+		mp.blsSigCache.Add(m.Cid(), m.Signature)
+	}
 
 	if _, err := mp.sm.ChainStore().PutMessage(m); err != nil {
 		log.Warnf("mpooladd cs.PutMessage failed: %s", err)
@@ -309,6 +318,18 @@ func (mp *MessagePool) HeadChange(revert []*types.TipSet, apply []*types.TipSet)
 }
 
 func (mp *MessagePool) RecoverSig(msg *types.Message) *types.SignedMessage {
-	// TODO: persist signatures for BLS messages for a little while in case of reorgs
-	return nil
+	val, ok := mp.blsSigCache.Get(msg.Cid())
+	if !ok {
+		return nil
+	}
+	sig, ok := val.(*types.Signature)
+	if !ok {
+		log.Warnf("value in signature cache was not a signature (got %T)", val)
+		return nil
+	}
+
+	return &types.SignedMessage{
+		Message:   *msg,
+		Signature: *sig,
+	}
 }