diff --git a/res/css/_components.scss b/res/css/_components.scss
index c47222da59..4081e49630 100644
--- a/res/css/_components.scss
+++ b/res/css/_components.scss
@@ -67,6 +67,7 @@
 @import "./views/dialogs/_RestoreKeyBackupDialog.scss";
 @import "./views/dialogs/_RoomSettingsDialog.scss";
 @import "./views/dialogs/_RoomUpgradeDialog.scss";
+@import "./views/dialogs/_RoomUpgradeWarningDialog.scss";
 @import "./views/dialogs/_SetEmailDialog.scss";
 @import "./views/dialogs/_SetMxIdDialog.scss";
 @import "./views/dialogs/_SetPasswordDialog.scss";
diff --git a/res/css/views/dialogs/_RoomUpgradeWarningDialog.scss b/res/css/views/dialogs/_RoomUpgradeWarningDialog.scss
new file mode 100644
index 0000000000..a40c591f6c
--- /dev/null
+++ b/res/css/views/dialogs/_RoomUpgradeWarningDialog.scss
@@ -0,0 +1,29 @@
+/*
+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.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+.mx_RoomUpgradeWarningDialog .mx_SettingsFlag {
+    .mx_ToggleSwitch {
+        display: inline-block;
+        vertical-align: middle;
+        margin-right: 8px;
+    }
+
+    .mx_SettingsFlag_label {
+        display: inline-block;
+        vertical-align: middle;
+    }
+}
+
diff --git a/src/RoomInvite.js b/src/RoomInvite.js
index b2b8689174..48baad5d9f 100644
--- a/src/RoomInvite.js
+++ b/src/RoomInvite.js
@@ -153,13 +153,8 @@ function _onStartDmFinished(shouldInvite, addrs) {
     }
 }
 
-function _onRoomInviteFinished(roomId, shouldInvite, addrs) {
-    if (!shouldInvite) return;
-
-    const addrTexts = addrs.map((addr) => addr.address);
-
-    // Invite new users to a room
-    inviteMultipleToRoom(roomId, addrTexts).then((result) => {
+export function inviteUsersToRoom(roomId, userIds) {
+    return inviteMultipleToRoom(roomId, userIds).then((result) => {
         const room = MatrixClientPeg.get().getRoom(roomId);
         return _showAnyInviteErrors(result.states, room, result.inviter);
     }).catch((err) => {
@@ -172,6 +167,15 @@ function _onRoomInviteFinished(roomId, shouldInvite, addrs) {
     });
 }
 
+function _onRoomInviteFinished(roomId, shouldInvite, addrs) {
+    if (!shouldInvite) return;
+
+    const addrTexts = addrs.map((addr) => addr.address);
+
+    // Invite new users to a room
+    inviteUsersToRoom(roomId, addrTexts);
+}
+
 // TODO: Immutable DMs replaces this
 function _isDmChat(addrTexts) {
     if (addrTexts.length === 1 && getAddressType(addrTexts[0]) === 'mx-user-id') {
diff --git a/src/SlashCommands.js b/src/SlashCommands.js
index 31e7ca4f39..dc16618a21 100644
--- a/src/SlashCommands.js
+++ b/src/SlashCommands.js
@@ -32,6 +32,7 @@ import { getAddressType } from './UserAddress';
 import { abbreviateUrl } from './utils/UrlUtils';
 import { getDefaultIdentityServerUrl, useDefaultIdentityServer } from './utils/IdentityServerUtils';
 import {isPermalinkHost, parsePermalink} from "./utils/permalinks/Permalinks";
+import {inviteUsersToRoom} from "./RoomInvite";
 
 const singleMxcUpload = async () => {
     return new Promise((resolve) => {
@@ -154,70 +155,54 @@ export const CommandMap = {
                     return reject(_t("You do not have the required permissions to use this command."));
                 }
 
+                const RoomUpgradeWarningDialog = sdk.getComponent("dialogs.RoomUpgradeWarningDialog");
+
                 const {finished} = Modal.createTrackedDialog('Slash Commands', 'upgrade room confirmation',
-                    QuestionDialog, {
-                    title: _t('Room upgrade confirmation'),
-                    description: (
-                        <div>
-                            <p>{_t("Upgrading a room can be destructive and isn't always necessary.")}</p>
-                            <p>
-                                {_t(
-                                    "Room upgrades are usually recommended when a room version is considered " +
-                                    "<i>unstable</i>. Unstable room versions might have bugs, missing features, or " +
-                                    "security vulnerabilities.",
-                                    {}, {
-                                        "i": (sub) => <i>{sub}</i>,
-                                    },
-                                )}
-                            </p>
-                            <p>
-                                {_t(
-                                    "Room upgrades usually only affect <i>server-side</i> processing of the " +
-                                    "room. If you're having problems with your Riot client, please file an issue " +
-                                    "with <issueLink />.",
-                                    {}, {
-                                        "i": (sub) => <i>{sub}</i>,
-                                        "issueLink": () => {
-                                            return <a href="https://github.com/vector-im/riot-web/issues/new/choose"
-                                                      target="_blank" rel="noopener">
-                                                https://github.com/vector-im/riot-web/issues/new/choose
-                                            </a>;
-                                        },
-                                    },
-                                )}
-                            </p>
-                            <p>
-                                {_t(
-                                    "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room " +
-                                    "members to the new version of the room.</i> We'll post a link to the new room " +
-                                    "in the old version of the room - room members will have to click this link to " +
-                                    "join the new room.",
-                                    {}, {
-                                        "b": (sub) => <b>{sub}</b>,
-                                        "i": (sub) => <i>{sub}</i>,
-                                    },
-                                )}
-                            </p>
-                            <p>
-                                {_t(
-                                    "Please confirm that you'd like to go forward with upgrading this room " +
-                                    "from <oldVersion /> to <newVersion />.",
-                                    {},
-                                    {
-                                        oldVersion: () => <code>{room ? room.getVersion() : "1"}</code>,
-                                        newVersion: () => <code>{args}</code>,
-                                    },
-                                )}
-                            </p>
-                        </div>
-                    ),
-                    button: _t("Upgrade"),
-                });
+                    RoomUpgradeWarningDialog, {roomId: roomId, targetVersion: args});
 
-                return success(finished.then(([confirm]) => {
-                    if (!confirm) return;
+                return success(finished.then(async ([resp]) => {
+                    if (!resp.continue) return;
 
-                    return cli.upgradeRoom(roomId, args);
+                    let checkForUpgradeFn;
+                    try {
+                        const upgradePromise = cli.upgradeRoom(roomId, args);
+
+                        // We have to wait for the js-sdk to give us the room back so
+                        // we can more effectively abuse the MultiInviter behaviour
+                        // which heavily relies on the Room object being available.
+                        if (resp.invite) {
+                            checkForUpgradeFn = async (newRoom) => {
+                                // The upgradePromise should be done by the time we await it here.
+                                const {replacement_room: newRoomId} = await upgradePromise;
+                                if (newRoom.roomId !== newRoomId) return;
+
+                                const joinedMembers = room.getJoinedMembers()
+                                    .map(m => m.userId).filter(m => m !== cli.getUserId());
+
+                                if (joinedMembers.length > 0) {
+                                    // Errors are handled internally to this function
+                                    await inviteUsersToRoom(newRoomId, joinedMembers);
+                                }
+
+                                cli.removeListener('Room', checkForUpgradeFn);
+                            };
+                            cli.on('Room', checkForUpgradeFn);
+                        }
+
+                        // We have to await after so that the checkForUpgradesFn has a proper reference
+                        // to the new room's ID.
+                        await upgradePromise;
+                    } catch (e) {
+                        console.error(e);
+
+                        if (checkForUpgradeFn) cli.removeListener('Room', checkForUpgradeFn);
+
+                        const ErrorDialog = sdk.getComponent('dialogs.ErrorDialog');
+                        Modal.createTrackedDialog('Slash Commands', 'room upgrade error', ErrorDialog, {
+                            title: _t('Error upgrading room'),
+                            description: _t('Double check that your server supports the room version chosen and try again.'),
+                        });
+                    }
                 }));
             }
             return reject(this.getUsage());
diff --git a/src/components/views/dialogs/RoomUpgradeWarningDialog.js b/src/components/views/dialogs/RoomUpgradeWarningDialog.js
new file mode 100644
index 0000000000..3a243a2d93
--- /dev/null
+++ b/src/components/views/dialogs/RoomUpgradeWarningDialog.js
@@ -0,0 +1,136 @@
+/*
+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.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+import React from 'react';
+import PropTypes from 'prop-types';
+import {_t} from "../../../languageHandler";
+import sdk from "../../../index";
+import LabelledToggleSwitch from "../elements/LabelledToggleSwitch";
+import MatrixClientPeg from "../../../MatrixClientPeg";
+
+export default class RoomUpgradeWarningDialog extends React.Component {
+    static propTypes = {
+        onFinished: PropTypes.func.isRequired,
+        roomId: PropTypes.string.isRequired,
+        targetVersion: PropTypes.string.isRequired,
+    };
+
+    constructor(props) {
+        super(props);
+
+        const room = MatrixClientPeg.get().getRoom(this.props.roomId);
+        const joinRules = room ? room.currentState.getStateEvents("m.room.join_rules", "") : null;
+        const isPrivate = joinRules ? joinRules.getContent()['join_rule'] !== 'public' : true;
+        this.state = {
+            currentVersion: room ? room.getVersion() : "1",
+            isPrivate,
+            inviteUsersToNewRoom: true,
+        };
+    }
+
+    _onContinue = () => {
+        this.props.onFinished({continue: true, invite: this.state.isPrivate && this.state.inviteUsersToNewRoom});
+    };
+
+    _onCancel = () => {
+        this.props.onFinished({continue: false, invite: false});
+    };
+
+    _onInviteUsersToggle = (newVal) => {
+        this.setState({inviteUsersToNewRoom: newVal});
+    };
+
+    render() {
+        const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
+        const DialogButtons = sdk.getComponent('views.elements.DialogButtons');
+
+        let inviteToggle = null;
+        if (this.state.isPrivate) {
+            inviteToggle = (
+                <LabelledToggleSwitch
+                    value={this.state.inviteUsersToNewRoom} toggleInFront={true}
+                    onChange={this._onInviteUsersToggle}
+                    label={_t("Invite joined members to the new room automatically")} />
+            );
+        }
+
+        return (
+            <BaseDialog className='mx_RoomUpgradeWarningDialog' hasCancel={true}
+                        onFinished={this.props.onFinished}
+                        title={_t("Room upgrade confirmation")}>
+                <div>
+                    <p>{_t("Upgrading a room can be destructive and isn't always necessary.")}</p>
+                    <p>
+                        {_t(
+                            "Room upgrades are usually recommended when a room version is considered " +
+                            "<i>unstable</i>. Unstable room versions might have bugs, missing features, or " +
+                            "security vulnerabilities.",
+                            {}, {
+                                "i": (sub) => <i>{sub}</i>,
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "Room upgrades usually only affect <i>server-side</i> processing of the " +
+                            "room. If you're having problems with your Riot client, please file an issue " +
+                            "with <issueLink />.",
+                            {}, {
+                                "i": (sub) => <i>{sub}</i>,
+                                "issueLink": () => {
+                                    return <a href="https://github.com/vector-im/riot-web/issues/new/choose"
+                                              target="_blank" rel="noopener">
+                                        https://github.com/vector-im/riot-web/issues/new/choose
+                                    </a>;
+                                },
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room " +
+                            "members to the new version of the room.</i> We'll post a link to the new room " +
+                            "in the old version of the room - room members will have to click this link to " +
+                            "join the new room.",
+                            {}, {
+                                "b": (sub) => <b>{sub}</b>,
+                                "i": (sub) => <i>{sub}</i>,
+                            },
+                        )}
+                    </p>
+                    <p>
+                        {_t(
+                            "Please confirm that you'd like to go forward with upgrading this room " +
+                            "from <oldVersion /> to <newVersion />.",
+                            {},
+                            {
+                                oldVersion: () => <code>{this.state.currentVersion}</code>,
+                                newVersion: () => <code>{this.props.targetVersion}</code>,
+                            },
+                        )}
+                    </p>
+                    {inviteToggle}
+                </div>
+                <DialogButtons
+                    primaryButton={_t("Continue")}
+                    onPrimaryButtonClick={this._onContinue}
+                    cancelButton={_t("Cancel")}
+                    onCancel={this._onCancel}
+                />
+            </BaseDialog>
+        );
+    }
+}
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index 9136f432dd..7b8da63377 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -154,13 +154,8 @@
     "To use it, just wait for autocomplete results to load and tab through them.": "To use it, just wait for autocomplete results to load and tab through them.",
     "Upgrades a room to a new version": "Upgrades a room to a new version",
     "You do not have the required permissions to use this command.": "You do not have the required permissions to use this command.",
-    "Room upgrade confirmation": "Room upgrade confirmation",
-    "Upgrading a room can be destructive and isn't always necessary.": "Upgrading a room can be destructive and isn't always necessary.",
-    "Room upgrades are usually recommended when a room version is considered <i>unstable</i>. Unstable room versions might have bugs, missing features, or security vulnerabilities.": "Room upgrades are usually recommended when a room version is considered <i>unstable</i>. Unstable room versions might have bugs, missing features, or security vulnerabilities.",
-    "Room upgrades usually only affect <i>server-side</i> processing of the room. If you're having problems with your Riot client, please file an issue with <issueLink />.": "Room upgrades usually only affect <i>server-side</i> processing of the room. If you're having problems with your Riot client, please file an issue with <issueLink />.",
-    "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room members to the new version of the room.</i> We'll post a link to the new room in the old version of the room - room members will have to click this link to join the new room.": "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room members to the new version of the room.</i> We'll post a link to the new room in the old version of the room - room members will have to click this link to join the new room.",
-    "Please confirm that you'd like to go forward with upgrading this room from <oldVersion /> to <newVersion />.": "Please confirm that you'd like to go forward with upgrading this room from <oldVersion /> to <newVersion />.",
-    "Upgrade": "Upgrade",
+    "Error upgrading room": "Error upgrading room",
+    "Double check that your server supports the room version chosen and try again.": "Double check that your server supports the room version chosen and try again.",
     "Changes your display nickname": "Changes your display nickname",
     "Changes your display nickname in the current room only": "Changes your display nickname in the current room only",
     "Changes the avatar of the current room": "Changes the avatar of the current room",
@@ -715,6 +710,7 @@
     "Camera": "Camera",
     "Voice & Video": "Voice & Video",
     "This room is not accessible by remote Matrix servers": "This room is not accessible by remote Matrix servers",
+    "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room members to the new version of the room.</i> We'll post a link to the new room in the old version of the room - room members will have to click this link to join the new room.": "<b>Warning</b>: Upgrading a room will <i>not automatically migrate room members to the new version of the room.</i> We'll post a link to the new room in the old version of the room - room members will have to click this link to join the new room.",
     "Upgrade this room to the recommended room version": "Upgrade this room to the recommended room version",
     "this room": "this room",
     "View older messages in %(roomName)s.": "View older messages in %(roomName)s.",
@@ -1430,6 +1426,12 @@
     "Update any local room aliases to point to the new room": "Update any local room aliases to point to the new room",
     "Stop users from speaking in the old version of the room, and post a message advising users to move to the new room": "Stop users from speaking in the old version of the room, and post a message advising users to move to the new room",
     "Put a link back to the old room at the start of the new room so people can see old messages": "Put a link back to the old room at the start of the new room so people can see old messages",
+    "Invite joined members to the new room automatically": "Invite joined members to the new room automatically",
+    "Room upgrade confirmation": "Room upgrade confirmation",
+    "Upgrading a room can be destructive and isn't always necessary.": "Upgrading a room can be destructive and isn't always necessary.",
+    "Room upgrades are usually recommended when a room version is considered <i>unstable</i>. Unstable room versions might have bugs, missing features, or security vulnerabilities.": "Room upgrades are usually recommended when a room version is considered <i>unstable</i>. Unstable room versions might have bugs, missing features, or security vulnerabilities.",
+    "Room upgrades usually only affect <i>server-side</i> processing of the room. If you're having problems with your Riot client, please file an issue with <issueLink />.": "Room upgrades usually only affect <i>server-side</i> processing of the room. If you're having problems with your Riot client, please file an issue with <issueLink />.",
+    "Please confirm that you'd like to go forward with upgrading this room from <oldVersion /> to <newVersion />.": "Please confirm that you'd like to go forward with upgrading this room from <oldVersion /> to <newVersion />.",
     "Sign out and remove encryption keys?": "Sign out and remove encryption keys?",
     "Clear Storage and Sign Out": "Clear Storage and Sign Out",
     "Send Logs": "Send Logs",
diff --git a/src/utils/MultiInviter.js b/src/utils/MultiInviter.js
index 8b952a2b5b..887d829d76 100644
--- a/src/utils/MultiInviter.js
+++ b/src/utils/MultiInviter.js
@@ -154,6 +154,8 @@ export default class MultiInviter {
                     return;
                 }
 
+                console.error(err);
+
                 let errorText;
                 let fatal = false;
                 if (err.errcode === 'M_FORBIDDEN') {