diff --git a/signer/core/gnosis_safe.go b/signer/core/gnosis_safe.go
index 016b1fff3..1b88db1af 100644
--- a/signer/core/gnosis_safe.go
+++ b/signer/core/gnosis_safe.go
@@ -31,6 +31,7 @@ type GnosisSafeTx struct {
 	SafeTxGas      big.Int                 `json:"safeTxGas"`
 	Nonce          big.Int                 `json:"nonce"`
 	InputExpHash   common.Hash             `json:"safeTxHash"`
+	ChainId        *math.HexOrDecimal256   `json:"chainId,omitempty"`
 }
 
 // ToTypedData converts the tx to a EIP-712 Typed Data structure for signing
@@ -39,9 +40,14 @@ func (tx *GnosisSafeTx) ToTypedData() apitypes.TypedData {
 	if tx.Data != nil {
 		data = *tx.Data
 	}
+	var domainType = []apitypes.Type{{Name: "verifyingContract", Type: "address"}}
+	if tx.ChainId != nil {
+		domainType = append([]apitypes.Type{{Name: "chainId", Type: "uint256"}}, domainType[0])
+	}
+
 	gnosisTypedData := apitypes.TypedData{
 		Types: apitypes.Types{
-			"EIP712Domain": []apitypes.Type{{Name: "verifyingContract", Type: "address"}},
+			"EIP712Domain": domainType,
 			"SafeTx": []apitypes.Type{
 				{Name: "to", Type: "address"},
 				{Name: "value", Type: "uint256"},
@@ -57,6 +63,7 @@ func (tx *GnosisSafeTx) ToTypedData() apitypes.TypedData {
 		},
 		Domain: apitypes.TypedDataDomain{
 			VerifyingContract: tx.Safe.Address().Hex(),
+			ChainId:           tx.ChainId,
 		},
 		PrimaryType: "SafeTx",
 		Message: apitypes.TypedDataMessage{
@@ -88,6 +95,7 @@ func (tx *GnosisSafeTx) ArgsForValidation() *apitypes.SendTxArgs {
 		Nonce:    hexutil.Uint64(tx.Nonce.Uint64()),
 		Data:     tx.Data,
 		Input:    nil,
+		ChainID:  (*hexutil.Big)(tx.ChainId),
 	}
 	return args
 }
diff --git a/signer/core/signed_data_test.go b/signer/core/signed_data_test.go
index 1d972d296..e2aff09b9 100644
--- a/signer/core/signed_data_test.go
+++ b/signer/core/signed_data_test.go
@@ -532,3 +532,133 @@ func TestGnosisCustomData(t *testing.T) {
 		t.Fatalf("Error, got %x, wanted %x", sighash, expSigHash)
 	}
 }
+
+var gnosisTypedDataWithChainId = `
+{
+	"types": {
+    "EIP712Domain": [
+        { "type": "uint256", "name": "chainId" },
+        { "type": "address", "name": "verifyingContract" }
+    ],
+		"SafeTx": [
+			{ "type": "address", "name": "to" },
+			{ "type": "uint256", "name": "value" },
+			{ "type": "bytes", "name": "data" },
+			{ "type": "uint8", "name": "operation" },
+			{ "type": "uint256", "name": "safeTxGas" },
+			{ "type": "uint256", "name": "baseGas" },
+			{ "type": "uint256", "name": "gasPrice" },
+			{ "type": "address", "name": "gasToken" },
+			{ "type": "address", "name": "refundReceiver" },
+			{ "type": "uint256", "name": "nonce" }
+		]
+	},
+	"domain": {
+		"verifyingContract": "0x111dAE35D176A9607053e0c46e91F36AFbC1dc57",
+		"chainId": "4"
+	},
+	"primaryType": "SafeTx",
+	"message": {
+		"to": "0x5592EC0cfb4dbc12D3aB100b257153436a1f0FEa",
+		"value": "0",
+		"data": "0xa9059cbb00000000000000000000000099d580d3a7fe7bd183b2464517b2cd7ce5a8f15a0000000000000000000000000000000000000000000000000de0b6b3a7640000",
+		"operation": 0,
+		"safeTxGas": 0,
+		"baseGas": 0,
+		"gasPrice": "0",
+		"gasToken": "0x0000000000000000000000000000000000000000",
+		"refundReceiver": "0x0000000000000000000000000000000000000000",
+		"nonce": 15
+	}
+}`
+
+var gnosisTxWithChainId = `
+{
+	"safe": "0x111dAE35D176A9607053e0c46e91F36AFbC1dc57",
+	"to": "0x5592EC0cfb4dbc12D3aB100b257153436a1f0FEa",
+	"value": "0",
+	"data": "0xa9059cbb00000000000000000000000099d580d3a7fe7bd183b2464517b2cd7ce5a8f15a0000000000000000000000000000000000000000000000000de0b6b3a7640000",
+	"operation": 0,
+	"gasToken": "0x0000000000000000000000000000000000000000",
+	"safeTxGas": 0,
+	"baseGas": 0,
+	"gasPrice": "0",
+	"refundReceiver": "0x0000000000000000000000000000000000000000",
+	"nonce": 15,
+	"executionDate": "2022-01-10T20:00:12Z",
+	"submissionDate": "2022-01-10T19:59:59.689989Z",
+	"modified": "2022-01-10T20:00:31.903635Z",
+	"blockNumber": 9968802,
+	"transactionHash": "0xc9fef30499ee8984974ab9dddd9d15c2a97c1a4393935dceed5efc3af9fc41a4",
+	"safeTxHash": "0x6619dab5401503f2735256e12b898e69eb701d6a7e0d07abf1be4bb8aebfba29",
+	"executor": "0xbc2BB26a6d821e69A38016f3858561a1D80d4182",
+	"isExecuted": true,
+	"isSuccessful": true,
+	"ethGasPrice": "2500000009",
+	"gasUsed": 82902,
+	"fee": "207255000746118",
+	"chainId": "4",
+	"origin": null,
+	"dataDecoded": {
+		"method": "transfer",
+		"parameters": [
+				{
+				"name": "to",
+				"type": "address",
+				"value": "0x99D580d3a7FE7BD183b2464517B2cD7ce5A8F15A"
+				},
+				{
+				"name": "value",
+				"type": "uint256",
+				"value": "1000000000000000000"
+				}
+		]
+	},
+	"confirmationsRequired": 1,
+	"confirmations": [
+		{
+		"owner": "0xbc2BB26a6d821e69A38016f3858561a1D80d4182",
+		"submissionDate": "2022-01-10T19:59:59.722500Z",
+		"transactionHash": null,
+		"signature": "0x5ca34641bcdee06e7b99143bfe34778195ca41022bd35837b96c204c7786be9d6dfa6dba43b53cd92da45ac728899e1561b232d28f38ba82df45f164caba38be1b",
+		"signatureType": "EOA"
+		}
+	],
+	"signatures": "0x5ca34641bcdee06e7b99143bfe34778195ca41022bd35837b96c204c7786be9d6dfa6dba43b53cd92da45ac728899e1561b232d28f38ba82df45f164caba38be1b"
+}
+`
+
+func TestGnosisTypedDataWithChainId(t *testing.T) {
+	var td apitypes.TypedData
+	err := json.Unmarshal([]byte(gnosisTypedDataWithChainId), &td)
+	if err != nil {
+		t.Fatalf("unmarshalling failed '%v'", err)
+	}
+	_, sighash, err := sign(td)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expSigHash := common.FromHex("0x6619dab5401503f2735256e12b898e69eb701d6a7e0d07abf1be4bb8aebfba29")
+	if !bytes.Equal(expSigHash, sighash) {
+		t.Fatalf("Error, got %x, wanted %x", sighash, expSigHash)
+	}
+}
+
+// TestGnosisCustomData tests the scenario where a user submits only the gnosis-safe
+// specific data, and we fill the TypedData struct on our side
+func TestGnosisCustomDataWithChainId(t *testing.T) {
+	var tx core.GnosisSafeTx
+	err := json.Unmarshal([]byte(gnosisTxWithChainId), &tx)
+	if err != nil {
+		t.Fatal(err)
+	}
+	var td = tx.ToTypedData()
+	_, sighash, err := sign(td)
+	if err != nil {
+		t.Fatal(err)
+	}
+	expSigHash := common.FromHex("0x6619dab5401503f2735256e12b898e69eb701d6a7e0d07abf1be4bb8aebfba29")
+	if !bytes.Equal(expSigHash, sighash) {
+		t.Fatalf("Error, got %x, wanted %x", sighash, expSigHash)
+	}
+}