diff --git a/electrum/gui/qml/components/ServerConfigDialog.qml b/electrum/gui/qml/components/ServerConfigDialog.qml
index 80cc54a31..9fed62953 100644
--- a/electrum/gui/qml/components/ServerConfigDialog.qml
+++ b/electrum/gui/qml/components/ServerConfigDialog.qml
@@ -39,6 +39,7 @@ ElDialog {
         FlatButton {
             Layout.fillWidth: true
             text: qsTr('Ok')
+            enabled: serverconfig.addressValid
             icon.source: '../../icons/confirmed.png'
             onClicked: {
                 let auto_connect = serverconfig.serverConnectMode == ServerConnectModeComboBox.Mode.Autoconnect
diff --git a/electrum/gui/qml/components/controls/ServerConfig.qml b/electrum/gui/qml/components/controls/ServerConfig.qml
index 47bd4e680..aae493bae 100644
--- a/electrum/gui/qml/components/controls/ServerConfig.qml
+++ b/electrum/gui/qml/components/controls/ServerConfig.qml
@@ -12,6 +12,7 @@ Item {
     property bool showAutoselectServer: true
     property alias address: address_tf.text
     property alias serverConnectMode: server_connect_mode_cb.currentValue
+    property alias addressValid: address_tf.valid
 
     implicitHeight: rootLayout.height
 
@@ -28,6 +29,11 @@ Item {
 
             ServerConnectModeComboBox {
                 id: server_connect_mode_cb
+                onCurrentValueChanged: {
+                    if (currentValue == ServerConnectModeComboBox.Mode.Autoconnect) {
+                        address_tf.text = ""
+                    }
+                }
             }
 
             Item {
@@ -63,6 +69,26 @@ Item {
                 enabled: server_connect_mode_cb.currentValue != ServerConnectModeComboBox.Mode.Autoconnect
                 width: parent.width
                 inputMethodHints: Qt.ImhNoPredictiveText
+
+                property bool valid: true
+
+                function validate() {
+                    if (!enabled) {
+                        valid = true
+                        return
+                    }
+                    valid = Network.isValidServerAddress(address_tf.text)
+                }
+
+                onTextChanged: validate()
+                onEnabledChanged: validate()
+
+                Rectangle {
+                    anchors.fill: parent
+                    color: "red"
+                    opacity: 0.2
+                    visible: !parent.valid
+                }
             }
         }
 
diff --git a/electrum/gui/qml/components/wizard/WCServerConfig.qml b/electrum/gui/qml/components/wizard/WCServerConfig.qml
index bc784d1b6..b0ab17082 100644
--- a/electrum/gui/qml/components/wizard/WCServerConfig.qml
+++ b/electrum/gui/qml/components/wizard/WCServerConfig.qml
@@ -5,7 +5,7 @@ import QtQuick.Controls
 import "../controls"
 
 WizardComponent {
-    valid: true
+    valid: sc.addressValid
     last: true
     title: qsTr('Server')
 
diff --git a/electrum/gui/qml/qenetwork.py b/electrum/gui/qml/qenetwork.py
index b25712d13..fa088822d 100644
--- a/electrum/gui/qml/qenetwork.py
+++ b/electrum/gui/qml/qenetwork.py
@@ -206,6 +206,10 @@ class QENetwork(QObject, QtEventListener):
     def server(self):
         return self._server
 
+    @pyqtSlot(str, result=bool)
+    def isValidServerAddress(self, server: str) -> bool:
+        return ServerAddr.from_str_with_inference(server) is not None
+
     @pyqtSlot(str, bool, bool)
     def setServerParameters(self, server_str: str, auto_connect: bool, one_server: bool):
         net_params = self.network.get_parameters()