diff --git a/account.go b/account.go
index dfae15c..83af455 100644
--- a/account.go
+++ b/account.go
@@ -35,7 +35,8 @@ import (
 type Account struct {
 	name string
 	*wallet.Wallet
-	TxStore *txstore.Store
+	TxStore         *txstore.Store
+	lockedOutpoints map[btcwire.OutPoint]struct{}
 }
 
 // Lock locks the underlying wallet for an account.
@@ -432,6 +433,44 @@ func (a *Account) exportBase64() (map[string]string, error) {
 	return m, nil
 }
 
+// LockedOutpoint returns whether an outpoint has been marked as locked and
+// should not be used as an input for created transactions.
+func (a *Account) LockedOutpoint(op btcwire.OutPoint) bool {
+	_, locked := a.lockedOutpoints[op]
+	return locked
+}
+
+// LockOutpoint marks an outpoint as locked, that is, it should not be used as
+// an input for newly created transactions.
+func (a *Account) LockOutpoint(op btcwire.OutPoint) {
+	a.lockedOutpoints[op] = struct{}{}
+}
+
+// UnlockOutpoint marks an outpoint as unlocked, that is, it may be used as an
+// input for newly created transactions.
+func (a *Account) UnlockOutpoint(op btcwire.OutPoint) {
+	delete(a.lockedOutpoints, op)
+}
+
+// ResetLockedOutpoints resets the set of locked outpoints so all may be used
+// as inputs for new transactions.
+func (a *Account) ResetLockedOutpoints() {
+	a.lockedOutpoints = map[btcwire.OutPoint]struct{}{}
+}
+
+// LockedOutpoints returns a slice of currently locked outpoints.  This is
+// intended to be used by marshaling the result as a JSON array for
+// listlockunspent RPC results.
+func (a *Account) LockedOutpoints() []btcjson.TransactionInput {
+	locked := make([]btcjson.TransactionInput, len(a.lockedOutpoints))
+	i := 0
+	for op := range a.lockedOutpoints {
+		locked[i] = btcjson.TransactionInput{op.Hash.String(), op.Index}
+		i++
+	}
+	return locked
+}
+
 // Track requests btcd to send notifications of new transactions for
 // each address stored in a wallet.
 func (a *Account) Track() {
diff --git a/acctmgr.go b/acctmgr.go
index 0294b7a..8a72add 100644
--- a/acctmgr.go
+++ b/acctmgr.go
@@ -177,9 +177,10 @@ func openSavedAccount(name string, cfg *config) (*Account, error) {
 	wlt := new(wallet.Wallet)
 	txs := txstore.New()
 	a := &Account{
-		name:    name,
-		Wallet:  wlt,
-		TxStore: txs,
+		name:            name,
+		Wallet:          wlt,
+		TxStore:         txs,
+		lockedOutpoints: map[btcwire.OutPoint]struct{}{},
 	}
 
 	walletPath := accountFilename("wallet.bin", name, netdir)
@@ -708,8 +709,9 @@ func (am *AccountManager) CreateEncryptedWallet(passphrase []byte) error {
 	// manager.  Registering will fail if the new account can not be
 	// written immediately to disk.
 	a := &Account{
-		Wallet:  wlt,
-		TxStore: txstore.New(),
+		Wallet:          wlt,
+		TxStore:         txstore.New(),
+		lockedOutpoints: map[btcwire.OutPoint]struct{}{},
 	}
 	if err := am.RegisterNewAccount(a); err != nil {
 		return err
diff --git a/createtx.go b/createtx.go
index 998736f..e72f5bc 100644
--- a/createtx.go
+++ b/createtx.go
@@ -197,6 +197,12 @@ func (a *Account) txToPairs(pairs map[string]btcutil.Amount,
 					continue
 				}
 			}
+
+			// Locked unspent outputs are skipped.
+			if a.LockedOutpoint(*unspent[i].OutPoint()) {
+				continue
+			}
+
 			eligible = append(eligible, unspent[i])
 		}
 	}
diff --git a/createtx_test.go b/createtx_test.go
index 55ddfc3..307956a 100644
--- a/createtx_test.go
+++ b/createtx_test.go
@@ -89,7 +89,8 @@ func TestFakeTxs(t *testing.T) {
 		return
 	}
 	a := &Account{
-		Wallet: w,
+		Wallet:          w,
+		lockedOutpoints: map[btcwire.OutPoint]struct{}{},
 	}
 
 	w.Unlock([]byte("banana"))
diff --git a/rpcserver.go b/rpcserver.go
index d4e309d..8d95b57 100644
--- a/rpcserver.go
+++ b/rpcserver.go
@@ -728,6 +728,7 @@ func (s *rpcServer) PostClientRPC(w http.ResponseWriter, r *http.Request) {
 		id = cmd.Id()
 	}
 	if err != nil {
+		fmt.Printf("%s\n", rpcRequest)
 		_, err := w.Write(marshalError(idPointer(cmd.Id())))
 		if err != nil {
 			log.Warnf("Client sent invalid request but unable "+
@@ -828,10 +829,12 @@ var rpcHandlers = map[string]requestHandler{
 	"importprivkey":          ImportPrivKey,
 	"keypoolrefill":          KeypoolRefill,
 	"listaccounts":           ListAccounts,
+	"listlockunspent":        ListLockUnspent,
 	"listreceivedbyaddress":  ListReceivedByAddress,
 	"listsinceblock":         ListSinceBlock,
 	"listtransactions":       ListTransactions,
 	"listunspent":            ListUnspent,
+	"lockunspent":            LockUnspent,
 	"sendfrom":               SendFrom,
 	"sendmany":               SendMany,
 	"sendtoaddress":          SendToAddress,
@@ -853,9 +856,7 @@ var rpcHandlers = map[string]requestHandler{
 	"getwalletinfo":         Unimplemented,
 	"importwallet":          Unimplemented,
 	"listaddressgroupings":  Unimplemented,
-	"listlockunspent":       Unimplemented,
 	"listreceivedbyaccount": Unimplemented,
-	"lockunspent":           Unimplemented,
 	"move":                  Unimplemented,
 	"setaccount":            Unimplemented,
 	"stop":                  Unimplemented,
@@ -1589,6 +1590,20 @@ func ListAccounts(icmd btcjson.Cmd) (interface{}, error) {
 	return AcctMgr.ListAccounts(cmd.MinConf), nil
 }
 
+// ListLockUnspent handles a listlockunspent request by returning an array of
+// all locked outpoints.
+func ListLockUnspent(icmd btcjson.Cmd) (interface{}, error) {
+	// Due to our poor account support, this assumes only the default
+	// account is available.  When the keystore and account heirarchies are
+	// reversed, the locked outpoints mapping will cover all accounts.
+	a, err := AcctMgr.Account("")
+	if err != nil {
+		return nil, err
+	}
+
+	return a.LockedOutpoints(), nil
+}
+
 // ListReceivedByAddress handles a listreceivedbyaddress request by returning
 // a slice of objects, each one containing:
 //  "account": the account of the receiving address;
@@ -1851,6 +1866,41 @@ func ListUnspent(icmd btcjson.Cmd) (interface{}, error) {
 	return AcctMgr.ListUnspent(cmd.MinConf, cmd.MaxConf, addresses)
 }
 
+// LockUnspent handles the lockunspent command.
+func LockUnspent(icmd btcjson.Cmd) (interface{}, error) {
+	cmd, ok := icmd.(*btcjson.LockUnspentCmd)
+	if !ok {
+		return nil, btcjson.ErrInternal
+	}
+
+	// Due to our poor account support, this assumes only the default
+	// account is available.  When the keystore and account heirarchies are
+	// reversed, the locked outpoints mapping will cover all accounts.
+	a, err := AcctMgr.Account("")
+	if err != nil {
+		return nil, err
+	}
+
+	switch {
+	case cmd.Unlock && len(cmd.Transactions) == 0:
+		a.ResetLockedOutpoints()
+	default:
+		for _, input := range cmd.Transactions {
+			txSha, err := btcwire.NewShaHashFromStr(input.Txid)
+			if err != nil {
+				return nil, ParseError{err}
+			}
+			op := btcwire.OutPoint{Hash: *txSha, Index: input.Vout}
+			if cmd.Unlock {
+				a.UnlockOutpoint(op)
+			} else {
+				a.LockOutpoint(op)
+			}
+		}
+	}
+	return true, nil
+}
+
 // sendPairs is a helper routine to reduce duplicated code when creating and
 // sending payment transactions.
 func sendPairs(icmd btcjson.Cmd, account string, amounts map[string]btcutil.Amount,
diff --git a/txstore/serialization.go b/txstore/serialization.go
index dbc6780..3f8197f 100644
--- a/txstore/serialization.go
+++ b/txstore/serialization.go
@@ -566,7 +566,7 @@ func (t *txRecord) ReadFrom(r io.Reader) (int64, error) {
 				}
 			}
 
-			c := &credit{change, false, spentBy}
+			c := &credit{change, spentBy}
 			credits = append(credits, c)
 		}
 
diff --git a/txstore/tx.go b/txstore/tx.go
index 1076f13..6181d06 100644
--- a/txstore/tx.go
+++ b/txstore/tx.go
@@ -250,7 +250,6 @@ type debits struct {
 // credit describes a transaction output which was or is spendable by wallet.
 type credit struct {
 	change  bool
-	locked  bool
 	spentBy *BlockTxKey // nil if unspent
 }