diff --git a/go/common/viewingkey/viewing_key.go b/go/common/viewingkey/viewing_key.go
index 264e9e8460..79ff803f48 100644
--- a/go/common/viewingkey/viewing_key.go
+++ b/go/common/viewingkey/viewing_key.go
@@ -4,6 +4,7 @@ import (
 	"crypto/ecdsa"
 	"encoding/hex"
 	"fmt"
+	"strings"
 
 	"github.com/ethereum/go-ethereum/accounts"
 	"github.com/ethereum/go-ethereum/crypto"
@@ -103,8 +104,8 @@ func GenerateSignMessage(vkPubKey []byte) string {
 }
 
 // GenerateSignMessageOG creates the message to be signed by Obscuro Gateway (new format)
-// format is expected to be "Register <userID> for <Account>"
+// format is expected to be "Register <userID> for <Account>" (with the account in lowercase)
 func GenerateSignMessageOG(vkPubKey []byte, addr *gethcommon.Address) string {
 	userID := crypto.Keccak256Hash(vkPubKey).Bytes()
-	return fmt.Sprintf("Register %s for %s", hex.EncodeToString(userID), addr.Hex())
+	return fmt.Sprintf("Register %s for %s", hex.EncodeToString(userID), strings.ToLower(addr.Hex()))
 }
diff --git a/tools/walletextension/common/common.go b/tools/walletextension/common/common.go
index 27d7f17e0a..4b2fc51ca0 100644
--- a/tools/walletextension/common/common.go
+++ b/tools/walletextension/common/common.go
@@ -35,9 +35,8 @@ func BytesToPrivateKey(keyBytes []byte) (*ecies.PrivateKey, error) {
 }
 
 // CalculateUserID calculates userID from public key
-func CalculateUserID(pk *ecdsa.PrivateKey) []byte {
-	viewingPublicKeyBytes := crypto.CompressPubkey(&pk.PublicKey)
-	return crypto.Keccak256Hash(viewingPublicKeyBytes).Bytes()
+func CalculateUserID(publicKeyBytes []byte) []byte {
+	return crypto.Keccak256Hash(publicKeyBytes).Bytes()
 }
 
 // GetUserIDAndAddressFromMessage checks if message is in correct format and extracts userID and address from it
diff --git a/tools/walletextension/wallet_extension.go b/tools/walletextension/wallet_extension.go
index 4de5e91912..ede55e8d36 100644
--- a/tools/walletextension/wallet_extension.go
+++ b/tools/walletextension/wallet_extension.go
@@ -176,7 +176,7 @@ func (w *WalletExtension) GenerateAndStoreNewUser() (string, error) {
 	}
 
 	// create UserID and store it in the database with the private key
-	userID := common.CalculateUserID(viewingKeyPrivate)
+	userID := common.CalculateUserID(common.PublicKeyBytesFromPrivateKey(viewingPrivateKeyEcies))
 	err = w.storage.AddUser(userID, crypto.FromECDSA(viewingPrivateKeyEcies.ExportECDSA()))
 	if err != nil {
 		w.Logger().Error(fmt.Sprintf("failed to save user to the database: %s", err))