diff --git a/.circleci/config.yml b/.circleci/config.yml
index 914fa2ffd..75846029a 100644
--- a/.circleci/config.yml
+++ b/.circleci/config.yml
@@ -858,6 +858,11 @@ workflows:
           suite: itest-deals
           target: "./itests/deals_test.go"
       
+      - test:
+          name: test-itest-gas_estimation
+          suite: itest-gas_estimation
+          target: "./itests/gas_estimation_test.go"
+      
       - test:
           name: test-itest-gateway
           suite: itest-gateway
diff --git a/chain/stmgr/call.go b/chain/stmgr/call.go
index 29b44fda1..d066ddb16 100644
--- a/chain/stmgr/call.go
+++ b/chain/stmgr/call.go
@@ -12,6 +12,7 @@ import (
 
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-state-types/abi"
+	"github.com/filecoin-project/go-state-types/big"
 	"github.com/filecoin-project/go-state-types/crypto"
 
 	"github.com/filecoin-project/lotus/api"
@@ -156,6 +157,10 @@ func (sm *StateManager) CallWithGas(ctx context.Context, msg *types.Message, pri
 	ctx, span := trace.StartSpan(ctx, "statemanager.CallWithGas")
 	defer span.End()
 
+	// Copy the message as we'll be modifying the nonce.
+	msgCopy := *msg
+	msg = &msgCopy
+
 	if ts == nil {
 		ts = sm.cs.GetHeaviestTipSet()
 
@@ -273,9 +278,21 @@ func (sm *StateManager) CallWithGas(ctx context.Context, msg *types.Message, pri
 
 	}
 
+	// If the fee cap is set to zero, make gas free.
+	if msg.GasFeeCap.NilOrZero() {
+		// Now estimate with a new VM with no base fee.
+		vmopt.BaseFee = big.Zero()
+		vmopt.StateBase = stateCid
+
+		vmi, err = sm.newVM(ctx, vmopt)
+		if err != nil {
+			return nil, xerrors.Errorf("failed to set up estimation vm: %w", err)
+		}
+	}
+
 	ret, err := vmi.ApplyMessage(ctx, msgApply)
 	if err != nil {
-		return nil, xerrors.Errorf("apply message failed: %w", err)
+		return nil, xerrors.Errorf("gas estimation failed: %w", err)
 	}
 
 	var errs string
diff --git a/itests/deals_retry_deal_no_funds_test.go b/itests/deals_retry_deal_no_funds_test.go
index 317538cf1..98f99a4a2 100644
--- a/itests/deals_retry_deal_no_funds_test.go
+++ b/itests/deals_retry_deal_no_funds_test.go
@@ -28,6 +28,15 @@ var (
 )
 
 func TestDealsRetryLackOfFunds(t *testing.T) {
+	t.Run("cover-gas", func(t *testing.T) {
+		testDealsRetryLackOfFunds(t, types.NewInt(1020000000000))
+	})
+	t.Run("empty", func(t *testing.T) {
+		testDealsRetryLackOfFunds(t, types.NewInt(1))
+	})
+}
+
+func testDealsRetryLackOfFunds(t *testing.T, publishStorageAccountFunds abi.TokenAmount) {
 	//stm: @CHAIN_SYNCER_LOAD_GENESIS_001, @CHAIN_SYNCER_FETCH_TIPSET_001,
 	//stm: @CHAIN_SYNCER_START_001, @CHAIN_SYNCER_SYNC_001, @BLOCKCHAIN_BEACON_VALIDATE_BLOCK_VALUES_01
 	//stm: @CHAIN_SYNCER_COLLECT_CHAIN_001, @CHAIN_SYNCER_COLLECT_HEADERS_001, @CHAIN_SYNCER_VALIDATE_TIPSET_001
@@ -61,7 +70,6 @@ func TestDealsRetryLackOfFunds(t *testing.T) {
 		})),
 	)
 
-	publishStorageAccountFunds := types.NewInt(1020000000000)
 	minerFullNode, clientFullNode, miner, ens := kit.EnsembleTwoOne(t, kit.Account(publishStorageDealKey, publishStorageAccountFunds), kit.ConstructorOpts(opts), kit.MockProofs(), eightMBSectorsOpt)
 
 	kit.QuietMiningLogs()
@@ -178,69 +186,3 @@ func TestDealsRetryLackOfFunds_blockInPublishDeal(t *testing.T) {
 	case <-time.After(time.Second * 15):
 	}
 }
-
-func TestDealsRetryLackOfFunds_belowLimit(t *testing.T) {
-	//stm: @CHAIN_SYNCER_LOAD_GENESIS_001, @CHAIN_SYNCER_FETCH_TIPSET_001,
-	//stm: @CHAIN_SYNCER_START_001, @CHAIN_SYNCER_SYNC_001, @BLOCKCHAIN_BEACON_VALIDATE_BLOCK_VALUES_01
-	//stm: @CHAIN_SYNCER_COLLECT_CHAIN_001, @CHAIN_SYNCER_COLLECT_HEADERS_001, @CHAIN_SYNCER_VALIDATE_TIPSET_001
-	//stm: @CHAIN_SYNCER_NEW_PEER_HEAD_001, @CHAIN_SYNCER_VALIDATE_MESSAGE_META_001, @CHAIN_SYNCER_STOP_001
-	//stm: @CLIENT_STORAGE_DEALS_LIST_IMPORTS_001
-	ctx := context.Background()
-	kit.QuietMiningLogs()
-
-	// Allow 8MB sectors
-	eightMBSectorsOpt := kit.SectorSize(8 << 20)
-
-	publishStorageDealKey, err := key.GenerateKey(types.KTSecp256k1)
-	require.NoError(t, err)
-
-	opts := node.Options(
-		node.Override(new(*storageadapter.DealPublisher),
-			storageadapter.NewDealPublisher(nil, storageadapter.PublishMsgConfig{
-				Period:         publishPeriod,
-				MaxDealsPerMsg: maxDealsPerMsg,
-			}),
-		),
-		node.Override(new(*ctladdr.AddressSelector), modules.AddressSelector(&config.MinerAddressConfig{
-			DealPublishControl: []string{
-				publishStorageDealKey.Address.String(),
-			},
-			DisableOwnerFallback:  true,
-			DisableWorkerFallback: true,
-		})),
-	)
-
-	publishStorageAccountFunds := types.NewInt(1)
-	minerFullNode, clientFullNode, miner, ens := kit.EnsembleTwoOne(t, kit.Account(publishStorageDealKey, publishStorageAccountFunds), kit.ConstructorOpts(opts), kit.MockProofs(), eightMBSectorsOpt)
-
-	kit.QuietMiningLogs()
-
-	ens.
-		Start().
-		InterconnectAll().
-		BeginMining(blockTime)
-
-	_, err = minerFullNode.WalletImport(ctx, &publishStorageDealKey.KeyInfo)
-	require.NoError(t, err)
-
-	miner.SetControlAddresses(publishStorageDealKey.Address)
-
-	dh := kit.NewDealHarness(t, clientFullNode, miner, miner)
-
-	res, _ := clientFullNode.CreateImportFile(ctx, 0, 4<<20) // 4MiB file.
-	list, err := clientFullNode.ClientListImports(ctx)
-	require.NoError(t, err)
-	require.Len(t, list, 1)
-	require.Equal(t, res.Root, *list[0].Root)
-
-	dp := dh.DefaultStartDealParams()
-	dp.Data.Root = res.Root
-	dp.FastRetrieval = true
-	dp.EpochPrice = abi.NewTokenAmount(62500000) // minimum asking price.
-	deal := dh.StartDeal(ctx, dp)
-
-	err = dh.ExpectDealFailure(ctx, deal, "Actor balance less than needed")
-	if err != nil {
-		t.Fatal(err)
-	}
-}
diff --git a/itests/gas_estimation_test.go b/itests/gas_estimation_test.go
new file mode 100644
index 000000000..52d52be30
--- /dev/null
+++ b/itests/gas_estimation_test.go
@@ -0,0 +1,54 @@
+package itests
+
+import (
+	"context"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/filecoin-project/go-state-types/big"
+
+	"github.com/filecoin-project/lotus/api"
+	"github.com/filecoin-project/lotus/chain/actors/builtin/account"
+	"github.com/filecoin-project/lotus/chain/types"
+	"github.com/filecoin-project/lotus/itests/kit"
+)
+
+func TestEstimateGasNoFunds(t *testing.T) {
+	ctx := context.Background()
+
+	kit.QuietMiningLogs()
+
+	client, _, ens := kit.EnsembleMinimal(t, kit.MockProofs())
+	ens.InterconnectAll().BeginMining(10 * time.Millisecond)
+
+	// create a new address
+	addr, err := client.WalletNew(ctx, types.KTBLS)
+	require.NoError(t, err)
+
+	// Create that address.
+	msg := &types.Message{
+		From:  client.DefaultKey.Address,
+		To:    addr,
+		Value: big.Zero(),
+	}
+
+	sm, err := client.MpoolPushMessage(ctx, msg, nil)
+	require.NoError(t, err)
+
+	_, err = client.StateWaitMsg(ctx, sm.Cid(), 3, api.LookbackNoLimit, true)
+	require.NoError(t, err)
+
+	// Create that address.
+	msg2 := &types.Message{
+		From:   addr,
+		To:     client.DefaultKey.Address,
+		Method: account.Methods.PubkeyAddress,
+		Value:  big.Zero(),
+	}
+
+	limit, err := client.GasEstimateGasLimit(ctx, msg2, types.EmptyTSK)
+	require.NoError(t, err)
+	require.NotZero(t, limit)
+}
diff --git a/node/impl/full/gas.go b/node/impl/full/gas.go
index 1e8a00922..c179c27d6 100644
--- a/node/impl/full/gas.go
+++ b/node/impl/full/gas.go
@@ -258,8 +258,8 @@ func gasEstimateGasLimit(
 ) (int64, error) {
 	msg := *msgIn
 	msg.GasLimit = build.BlockGasLimit
-	msg.GasFeeCap = types.NewInt(uint64(build.MinimumBaseFee) + 1)
-	msg.GasPremium = types.NewInt(1)
+	msg.GasFeeCap = big.Zero()
+	msg.GasPremium = big.Zero()
 
 	fromA, err := smgr.ResolveToKeyAddress(ctx, msgIn.From, currTs)
 	if err != nil {
diff --git a/node/impl/full/mpool.go b/node/impl/full/mpool.go
index 2c9451079..e7a461784 100644
--- a/node/impl/full/mpool.go
+++ b/node/impl/full/mpool.go
@@ -9,6 +9,7 @@ import (
 	"golang.org/x/xerrors"
 
 	"github.com/filecoin-project/go-address"
+	"github.com/filecoin-project/go-state-types/big"
 
 	"github.com/filecoin-project/lotus/api"
 	"github.com/filecoin-project/lotus/chain/messagepool"
@@ -178,8 +179,9 @@ func (a *MpoolAPI) MpoolPushMessage(ctx context.Context, msg *types.Message, spe
 		return nil, xerrors.Errorf("mpool push: getting origin balance: %w", err)
 	}
 
-	if b.LessThan(msg.Value) {
-		return nil, xerrors.Errorf("mpool push: not enough funds: %s < %s", b, msg.Value)
+	requiredFunds := big.Add(msg.Value, msg.RequiredFunds())
+	if b.LessThan(requiredFunds) {
+		return nil, xerrors.Errorf("mpool push: not enough funds: %s < %s", b, requiredFunds)
 	}
 
 	// Sign and push the message