diff --git a/lnrpc/walletrpc/config_active.go b/lnrpc/walletrpc/config_active.go
index 77dc0e57..9804bc11 100644
--- a/lnrpc/walletrpc/config_active.go
+++ b/lnrpc/walletrpc/config_active.go
@@ -43,4 +43,8 @@ type Config struct {
 	// Sweeper is the central batching engine of lnd. It is responsible for
 	// sweeping inputs in batches back into the wallet.
 	Sweeper *sweep.UtxoSweeper
+
+	// Chain is an interface that the WalletKit will use to determine state
+	// about the backing chain of the wallet.
+	Chain lnwallet.BlockChainIO
 }
diff --git a/lnrpc/walletrpc/driver.go b/lnrpc/walletrpc/driver.go
index 4135d3aa..deb02a6e 100644
--- a/lnrpc/walletrpc/driver.go
+++ b/lnrpc/walletrpc/driver.go
@@ -51,6 +51,14 @@ func createNewSubServer(configRegistry lnrpc.SubServerConfigDispatcher) (lnrpc.S
 	case config.KeyRing == nil:
 		return nil, nil, fmt.Errorf("KeyRing must be set to create " +
 			"WalletKit RPC server")
+
+	case config.Sweeper == nil:
+		return nil, nil, fmt.Errorf("Sweeper must be set to create " +
+			"WalletKit RPC server")
+
+	case config.Chain == nil:
+		return nil, nil, fmt.Errorf("Chain must be set to create " +
+			"WalletKit RPC server")
 	}
 
 	return New(config)
diff --git a/lnrpc/walletrpc/walletkit_server.go b/lnrpc/walletrpc/walletkit_server.go
index 374983f4..b463774e 100644
--- a/lnrpc/walletrpc/walletkit_server.go
+++ b/lnrpc/walletrpc/walletkit_server.go
@@ -4,6 +4,7 @@ package walletrpc
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"os"
@@ -501,6 +502,12 @@ func (w *WalletKit) BumpFee(ctx context.Context,
 		return nil, err
 	}
 
+	// We're only able to bump the fee of unconfirmed transactions.
+	if utxo.Confirmations > 0 {
+		return nil, errors.New("unable to bump fee of a confirmed " +
+			"transaction")
+	}
+
 	var witnessType input.WitnessType
 	switch utxo.AddressType {
 	case lnwallet.WitnessPubKey:
@@ -519,7 +526,15 @@ func (w *WalletKit) BumpFee(ctx context.Context,
 		HashType: txscript.SigHashAll,
 	}
 
-	input := input.NewBaseInput(op, witnessType, signDesc, 0)
+	// We'll use the current height as the height hint since we're dealing
+	// with an unconfirmed transaction.
+	_, currentHeight, err := w.cfg.Chain.GetBestBlock()
+	if err != nil {
+		return nil, fmt.Errorf("unable to retrieve current height: %v",
+			err)
+	}
+
+	input := input.NewBaseInput(op, witnessType, signDesc, uint32(currentHeight))
 	if _, err = w.cfg.Sweeper.SweepInput(input, feePreference); err != nil {
 		return nil, err
 	}
diff --git a/subrpcserver_config.go b/subrpcserver_config.go
index 06b9dfc5..d00e3a43 100644
--- a/subrpcserver_config.go
+++ b/subrpcserver_config.go
@@ -152,6 +152,9 @@ func (s *subRPCServerConfigs) PopulateDependencies(cc *chainControl,
 			subCfgValue.FieldByName("Sweeper").Set(
 				reflect.ValueOf(sweeper),
 			)
+			subCfgValue.FieldByName("Chain").Set(
+				reflect.ValueOf(cc.chainIO),
+			)
 
 		case *autopilotrpc.Config:
 			subCfgValue := extractReflectValue(subCfg)