diff --git a/src/CallHandler.js b/src/CallHandler.js
index 40a8d426f8..f6b3e18538 100644
--- a/src/CallHandler.js
+++ b/src/CallHandler.js
@@ -1,6 +1,7 @@
 /*
 Copyright 2015, 2016 OpenMarket Ltd
 Copyright 2017, 2018 New Vector Ltd
+Copyright 2019 The Matrix.org Foundation C.I.C.
 
 Licensed under the Apache License, Version 2.0 (the "License");
 you may not use this file except in compliance with the License.
@@ -64,6 +65,7 @@ import { showUnknownDeviceDialogForCalls } from './cryptodevices';
 import WidgetUtils from './utils/WidgetUtils';
 import WidgetEchoStore from './stores/WidgetEchoStore';
 import {IntegrationManagers} from "./integrations/IntegrationManagers";
+import SettingsStore, { SettingLevel } from './settings/SettingsStore';
 
 global.mxCalls = {
     //room_id: MatrixCall
@@ -117,8 +119,7 @@ function _reAttemptCall(call) {
 
 function _setCallListeners(call) {
     call.on("error", function(err) {
-        console.error("Call error: %s", err);
-        console.error(err.stack);
+        console.error("Call error:", err);
         if (err.code === 'unknown_devices') {
             const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
 
@@ -146,8 +147,15 @@ function _setCallListeners(call) {
                 },
             });
         } else {
-            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
+            if (
+                MatrixClientPeg.get().getTurnServers().length === 0 &&
+                SettingsStore.getValue("fallbackICEServerAllowed") === null
+            ) {
+                _showICEFallbackPrompt();
+                return;
+            }
 
+            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
             Modal.createTrackedDialog('Call Failed', '', ErrorDialog, {
                 title: _t('Call Failed'),
                 description: err.message,
@@ -217,6 +225,36 @@ function _setCallState(call, roomId, status) {
     });
 }
 
+function _showICEFallbackPrompt() {
+    const cli = MatrixClientPeg.get();
+    const QuestionDialog = sdk.getComponent("dialogs.QuestionDialog");
+    const code = sub => <code>{sub}</code>;
+    Modal.createTrackedDialog('No TURN servers', '', QuestionDialog, {
+        title: _t("Call failed due to misconfigured server"),
+        description: <div>
+            <p>{_t(
+                "Please ask the administrator of your homeserver " +
+                "(<code>%(homeserverDomain)s</code>) to configure a TURN server in " +
+                "order for calls to work reliably.",
+                { homeserverDomain: cli.getDomain() }, { code },
+            )}</p>
+            <p>{_t(
+                "Alternatively, you can try to use the public server at " +
+                "<code>turn.matrix.org</code>, but this will not be as reliable, and " +
+                "it will share your IP address with that server. You can also manage " +
+                "this in Settings.",
+                null, { code },
+            )}</p>
+        </div>,
+        button: _t('Try using turn.matrix.org'),
+        cancelButton: _t('OK'),
+        onFinished: (allow) => {
+            SettingsStore.setValue("fallbackICEServerAllowed", null, SettingLevel.DEVICE, allow);
+            cli.setFallbackICEServerAllowed(allow);
+        },
+    }, null, true);
+}
+
 function _onAction(payload) {
     function placeCall(newCall) {
         _setCallListeners(newCall);
diff --git a/src/MatrixClientPeg.js b/src/MatrixClientPeg.js
index d2760bc82c..813f0ed87e 100644
--- a/src/MatrixClientPeg.js
+++ b/src/MatrixClientPeg.js
@@ -216,6 +216,7 @@ class MatrixClientPeg {
             deviceId: creds.deviceId,
             timelineSupport: true,
             forceTURN: !SettingsStore.getValue('webRtcAllowPeerToPeer', false),
+            fallbackICEServerAllowed: !!SettingsStore.getValue('fallbackICEServerAllowed'),
             verificationMethods: [verificationMethods.SAS],
             unstableClientRelationAggregation: true,
         };
diff --git a/src/components/views/settings/tabs/user/VoiceUserSettingsTab.js b/src/components/views/settings/tabs/user/VoiceUserSettingsTab.js
index eb85fe4e44..18ea5a82be 100644
--- a/src/components/views/settings/tabs/user/VoiceUserSettingsTab.js
+++ b/src/components/views/settings/tabs/user/VoiceUserSettingsTab.js
@@ -115,6 +115,10 @@ export default class VoiceUserSettingsTab extends React.Component {
         MatrixClientPeg.get().setForceTURN(!p2p);
     };
 
+    _changeFallbackICEServerAllowed = (allow) => {
+        MatrixClientPeg.get().setFallbackICEServerAllowed(allow);
+    };
+
     _renderDeviceOptions(devices, category) {
         return devices.map((d) => {
             return (<option key={`${category}-${d.deviceId}`} value={d.deviceId}>{d.label}</option>);
@@ -201,7 +205,16 @@ export default class VoiceUserSettingsTab extends React.Component {
                     {microphoneDropdown}
                     {webcamDropdown}
                     <SettingsFlag name='VideoView.flipVideoHorizontally' level={SettingLevel.ACCOUNT} />
-                    <SettingsFlag name='webRtcAllowPeerToPeer' level={SettingLevel.DEVICE} onChange={this._changeWebRtcMethod} />
+                    <SettingsFlag
+                        name='webRtcAllowPeerToPeer'
+                        level={SettingLevel.DEVICE}
+                        onChange={this._changeWebRtcMethod}
+                    />
+                    <SettingsFlag
+                        name='fallbackICEServerAllowed'
+                        level={SettingLevel.DEVICE}
+                        onChange={this._changeFallbackICEServerAllowed}
+                    />
                 </div>
             </div>
         );
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 0ca1ece48f..ce23180526 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -28,6 +28,11 @@
     "Answer": "Answer",
     "Call Timeout": "Call Timeout",
     "The remote side failed to pick up": "The remote side failed to pick up",
+    "Call failed due to misconfigured server": "Call failed due to misconfigured server",
+    "Please ask the administrator of your homeserver (<code>%(homeserverDomain)s</code>) to configure a TURN server in order for calls to work reliably.": "Please ask the administrator of your homeserver (<code>%(homeserverDomain)s</code>) to configure a TURN server in order for calls to work reliably.",
+    "Alternatively, you can try to use the public server at <code>turn.matrix.org</code>, but this will not be as reliable, and it will share your IP address with that server. You can also manage this in Settings.": "Alternatively, you can try to use the public server at <code>turn.matrix.org</code>, but this will not be as reliable, and it will share your IP address with that server. You can also manage this in Settings.",
+    "Try using turn.matrix.org": "Try using turn.matrix.org",
+    "OK": "OK",
     "Unable to capture screen": "Unable to capture screen",
     "Existing Call": "Existing Call",
     "You are already in a call.": "You are already in a call.",
@@ -355,6 +360,7 @@
     "Show recently visited rooms above the room list": "Show recently visited rooms above the room list",
     "Show hidden events in timeline": "Show hidden events in timeline",
     "Low bandwidth mode": "Low bandwidth mode",
+    "Allow fallback call assist server turn.matrix.org when your homeserver does not offer one (your IP address would be shared during a call)": "Allow fallback call assist server turn.matrix.org when your homeserver does not offer one (your IP address would be shared during a call)",
     "Collecting app version information": "Collecting app version information",
     "Collecting logs": "Collecting logs",
     "Uploading report": "Uploading report",
@@ -378,7 +384,6 @@
     "Decline": "Decline",
     "Accept": "Accept",
     "The other party cancelled the verification.": "The other party cancelled the verification.",
-    "OK": "OK",
     "Verified!": "Verified!",
     "You've successfully verified this user.": "You've successfully verified this user.",
     "Secure messages with this user are end-to-end encrypted and not able to be read by third parties.": "Secure messages with this user are end-to-end encrypted and not able to be read by third parties.",
diff --git a/src/settings/Settings.js b/src/settings/Settings.js
index 55085963d1..b33ef3f8d7 100644
--- a/src/settings/Settings.js
+++ b/src/settings/Settings.js
@@ -372,4 +372,13 @@ export const SETTINGS = {
         default: false,
         controller: new LowBandwidthController(),
     },
+    "fallbackICEServerAllowed": {
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS,
+        displayName: _td(
+            "Allow fallback call assist server turn.matrix.org when your homeserver " +
+            "does not offer one (your IP address would be shared during a call)",
+        ),
+        // This is a tri-state value, where `null` means "prompt the user".
+        default: null,
+    },
 };