diff --git a/pkg/rpc/request/param.go b/pkg/rpc/request/param.go
index 45249257b..d779f5d00 100644
--- a/pkg/rpc/request/param.go
+++ b/pkg/rpc/request/param.go
@@ -316,9 +316,14 @@ func (p *Param) UnmarshalJSON(data []byte) error {
 				}
 			case *signerWithWitnessAux:
 				aux := *val
+				accParam := Param{StringT, aux.Account}
+				acc, err := accParam.GetUint160FromAddressOrHex()
+				if err != nil {
+					return err
+				}
 				p.Value = SignerWithWitness{
 					Signer: transaction.Signer{
-						Account:          aux.Account,
+						Account:          acc,
 						Scopes:           aux.Scopes,
 						AllowedContracts: aux.AllowedContracts,
 						AllowedGroups:    aux.AllowedGroups,
@@ -341,7 +346,7 @@ func (p *Param) UnmarshalJSON(data []byte) error {
 // signerWithWitnessAux is an auxiluary struct for JSON marshalling. We need it because of
 // DisallowUnknownFields JSON marshaller setting.
 type signerWithWitnessAux struct {
-	Account            util.Uint160             `json:"account"`
+	Account            string                   `json:"account"`
 	Scopes             transaction.WitnessScope `json:"scopes"`
 	AllowedContracts   []util.Uint160           `json:"allowedcontracts,omitempty"`
 	AllowedGroups      []*keys.PublicKey        `json:"allowedgroups,omitempty"`
@@ -352,7 +357,7 @@ type signerWithWitnessAux struct {
 // MarshalJSON implements json.Unmarshaler interface.
 func (s *SignerWithWitness) MarshalJSON() ([]byte, error) {
 	signer := &signerWithWitnessAux{
-		Account:            s.Account,
+		Account:            s.Account.StringLE(),
 		Scopes:             s.Scopes,
 		AllowedContracts:   s.AllowedContracts,
 		AllowedGroups:      s.AllowedGroups,
diff --git a/pkg/rpc/request/param_test.go b/pkg/rpc/request/param_test.go
index 3df4a9667..61c3f8aa0 100644
--- a/pkg/rpc/request/param_test.go
+++ b/pkg/rpc/request/param_test.go
@@ -25,12 +25,15 @@ func TestParam_UnmarshalJSON(t *testing.T) {
                  {"contract": "f84d6a337fbc3d3a201d41da99e86b479e7a2554", "name":"my_pretty_notification"},
                  {"state": "HALT"},
                  {"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569"},
+                 {"account": "NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag", "scopes": "Global"},
                  [{"account": "0xcadb3dc2faa3ef14a13b619c9a43124755aa2569", "scopes": "Global"}]]`
 	contr, err := util.Uint160DecodeStringLE("f84d6a337fbc3d3a201d41da99e86b479e7a2554")
 	require.NoError(t, err)
 	name := "my_pretty_notification"
 	accountHash, err := util.Uint160DecodeStringLE("cadb3dc2faa3ef14a13b619c9a43124755aa2569")
 	require.NoError(t, err)
+	addrHash, err := address.StringToUint160("NYxb4fSZVKAz8YsgaPK2WkT3KcAE9b3Vag")
+	require.NoError(t, err)
 	expected := Params{
 		{
 			Type:  StringT,
@@ -112,6 +115,15 @@ func TestParam_UnmarshalJSON(t *testing.T) {
 				},
 			},
 		},
+		{
+			Type: SignerWithWitnessT,
+			Value: SignerWithWitness{
+				Signer: transaction.Signer{
+					Account: addrHash,
+					Scopes:  transaction.Global,
+				},
+			},
+		},
 		{
 			Type: ArrayT,
 			Value: []Param{
@@ -134,6 +146,8 @@ func TestParam_UnmarshalJSON(t *testing.T) {
 
 	msg = `[{"2": 3}]`
 	require.Error(t, json.Unmarshal([]byte(msg), &ps))
+	msg = `[{"account": "notanaccount", "scopes": "Global"}]`
+	require.Error(t, json.Unmarshal([]byte(msg), &ps))
 }
 
 func TestParamGetString(t *testing.T) {