diff --git a/pkg/wallet/account.go b/pkg/wallet/account.go
index 067d59e07..c3a0ba098 100644
--- a/pkg/wallet/account.go
+++ b/pkg/wallet/account.go
@@ -205,6 +205,9 @@ func NewAccountFromEncryptedWIF(wif string, pass string, scrypt keys.ScryptParam
 
 // ConvertMultisig sets a's contract to multisig contract with m sufficient signatures.
 func (a *Account) ConvertMultisig(m int, pubs []*keys.PublicKey) error {
+	if a.Locked {
+		return errors.New("account is locked")
+	}
 	var found bool
 	for i := range pubs {
 		if bytes.Equal(a.publicKey, pubs[i].Bytes()) {
diff --git a/pkg/wallet/account_test.go b/pkg/wallet/account_test.go
index d2b0374de..841201edb 100644
--- a/pkg/wallet/account_test.go
+++ b/pkg/wallet/account_test.go
@@ -179,6 +179,12 @@ func TestAccount_ConvertMultisig(t *testing.T) {
 		"03d90c07df63e690ce77912e10ab51acc944b66860237b608c4f8f8309e71ee699",
 	}
 
+	t.Run("locked", func(t *testing.T) {
+		a.Locked = true
+		pubs := convertPubs(t, hexs)
+		require.Error(t, a.ConvertMultisig(1, pubs))
+		a.Locked = false
+	})
 	t.Run("invalid number of signatures", func(t *testing.T) {
 		pubs := convertPubs(t, hexs)
 		require.Error(t, a.ConvertMultisig(0, pubs))