diff --git a/res/css/_components.scss b/res/css/_components.scss
index 173939e143..62cdb4533e 100644
--- a/res/css/_components.scss
+++ b/res/css/_components.scss
@@ -39,6 +39,7 @@
 @import "./views/dialogs/_EncryptedEventDialog.scss";
 @import "./views/dialogs/_GroupAddressPicker.scss";
 @import "./views/dialogs/_QuestionDialog.scss";
+@import "./views/dialogs/_RoomUpgradeDialog.scss";
 @import "./views/dialogs/_SetEmailDialog.scss";
 @import "./views/dialogs/_SetMxIdDialog.scss";
 @import "./views/dialogs/_SetPasswordDialog.scss";
@@ -99,6 +100,7 @@
 @import "./views/rooms/_RoomSettings.scss";
 @import "./views/rooms/_RoomTile.scss";
 @import "./views/rooms/_RoomTooltip.scss";
+@import "./views/rooms/_RoomUpgradeWarningBar.scss";
 @import "./views/rooms/_SearchBar.scss";
 @import "./views/rooms/_SearchableEntityList.scss";
 @import "./views/rooms/_Stickers.scss";
diff --git a/res/css/views/dialogs/_RoomUpgradeDialog.scss b/res/css/views/dialogs/_RoomUpgradeDialog.scss
new file mode 100644
index 0000000000..2e3ac5fdea
--- /dev/null
+++ b/res/css/views/dialogs/_RoomUpgradeDialog.scss
@@ -0,0 +1,19 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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_RoomUpgradeDialog {
+    padding-right: 70px;
+}
diff --git a/res/css/views/rooms/_RoomSettings.scss b/res/css/views/rooms/_RoomSettings.scss
index 4013af4c7c..f04042ea77 100644
--- a/res/css/views/rooms/_RoomSettings.scss
+++ b/res/css/views/rooms/_RoomSettings.scss
@@ -20,6 +20,7 @@ limitations under the License.
     margin-bottom: 20px;
 }
 
+.mx_RoomSettings_upgradeButton,
 .mx_RoomSettings_leaveButton,
 .mx_RoomSettings_unbanButton {
     @mixin mx_DialogButton;
@@ -27,11 +28,16 @@ limitations under the License.
     margin-right: 8px;
 }
 
+.mx_RoomSettings_upgradeButton,
 .mx_RoomSettings_leaveButton:hover,
 .mx_RoomSettings_unbanButton:hover {
     @mixin mx_DialogButton_hover;
 }
 
+.mx_RoomSettings_upgradeButton.danger {
+    @mixin mx_DialogButton_danger;
+}
+
 .mx_RoomSettings_integrationsButton_error {
     position: relative;
     cursor: not-allowed;
diff --git a/res/css/views/rooms/_RoomUpgradeWarningBar.scss b/res/css/views/rooms/_RoomUpgradeWarningBar.scss
new file mode 100644
index 0000000000..82785b82d2
--- /dev/null
+++ b/res/css/views/rooms/_RoomUpgradeWarningBar.scss
@@ -0,0 +1,48 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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_RoomUpgradeWarningBar {
+    text-align: center;
+    height: 176px;
+    background-color: $event-selected-color;
+    align-items: center;
+    flex-direction: column;
+    justify-content: center;
+    display: flex;
+    background-color: $preview-bar-bg-color;
+    -webkit-align-items: center;
+    padding-left: 20px;
+    padding-right: 20px;
+}
+
+.mx_RoomUpgradeWarningBar_header {
+    color: $warning-color;
+    font-weight: bold;
+}
+
+.mx_RoomUpgradeWarningBar_body {
+    color: $warning-color;
+}
+
+.mx_RoomUpgradeWarningBar_upgradelink {
+    color: $warning-color;
+    text-decoration: underline;
+}
+
+.mx_RoomUpgradeWarningBar_small {
+    color: $greyed-fg-color;
+    font-size: 70%;
+}
diff --git a/res/themes/light/css/_base.scss b/res/themes/light/css/_base.scss
index 7d004bd831..c7fd38259c 100644
--- a/res/themes/light/css/_base.scss
+++ b/res/themes/light/css/_base.scss
@@ -171,6 +171,10 @@ $progressbar-color: #000;
     outline: none;
 }
 
+@define-mixin mx_DialogButton_danger {
+    background-color: $warning-color;
+}
+
 @define-mixin mx_DialogButton_hover {
 }
 
diff --git a/src/components/structures/RoomView.js b/src/components/structures/RoomView.js
index 855090873f..5243cd15fa 100644
--- a/src/components/structures/RoomView.js
+++ b/src/components/structures/RoomView.js
@@ -1461,6 +1461,7 @@ module.exports = React.createClass({
         const RoomPreviewBar = sdk.getComponent("rooms.RoomPreviewBar");
         const Loader = sdk.getComponent("elements.Spinner");
         const TimelinePanel = sdk.getComponent("structures.TimelinePanel");
+        const RoomUpgradeWarningBar = sdk.getComponent("rooms.RoomUpgradeWarningBar");
 
         if (!this.state.room) {
             if (this.state.roomLoading || this.state.peekLoading) {
@@ -1586,6 +1587,11 @@ module.exports = React.createClass({
             />;
         }
 
+        const showRoomUpgradeBar = (
+            this.state.room.shouldUpgradeToVersion() &&
+            this.state.room.userMayUpgradeRoom(MatrixClientPeg.get().credentials.userId)
+        );
+
         let aux = null;
         let hideCancel = false;
         if (this.state.editingRoomSettings) {
@@ -1597,6 +1603,9 @@ module.exports = React.createClass({
         } else if (this.state.searching) {
             hideCancel = true; // has own cancel
             aux = <SearchBar ref="search_bar" searchInProgress={this.state.searchInProgress} onCancelClick={this.onCancelSearchClick} onSearch={this.onSearch} />;
+        } else if (showRoomUpgradeBar) {
+            aux = <RoomUpgradeWarningBar room={this.state.room} />;
+            hideCancel = true;
         } else if (this.state.showingPinned) {
             hideCancel = true; // has own cancel
             aux = <PinnedEventsPanel room={this.state.room} onCancelClick={this.onPinnedClick} />;
diff --git a/src/components/views/dialogs/RoomUpgradeDialog.js b/src/components/views/dialogs/RoomUpgradeDialog.js
new file mode 100644
index 0000000000..936ff745d1
--- /dev/null
+++ b/src/components/views/dialogs/RoomUpgradeDialog.js
@@ -0,0 +1,106 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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 sdk from '../../../index';
+import MatrixClientPeg from '../../../MatrixClientPeg';
+import Modal from '../../../Modal';
+import { _t } from '../../../languageHandler';
+
+export default React.createClass({
+    displayName: 'RoomUpgradeDialog',
+
+    propTypes: {
+        room: PropTypes.object.isRequired,
+        onFinished: PropTypes.func.isRequired,
+    },
+
+    componentWillMount: function() {
+        this._targetVersion = this.props.room.shouldUpgradeToVersion();
+    },
+
+    getInitialState: function() {
+        return {
+            busy: false,
+        };
+    },
+
+    _onCancelClick: function() {
+        this.props.onFinished(false);
+    },
+
+    _onUpgradeClick: function() {
+        this.setState({busy: true});
+        MatrixClientPeg.get().upgradeRoom(this.props.room.roomId, this._targetVersion).catch((err) => {
+            const ErrorDialog = sdk.getComponent("dialogs.ErrorDialog");
+            Modal.createTrackedDialog('Failed to upgrade room', '', ErrorDialog, {
+                title: _t("Failed to upgrade room"),
+                description: ((err && err.message) ? err.message : _t("The room upgrade could not be completed")),
+            });
+        }).finally(() => {
+            this.setState({busy: false});
+        });
+    },
+
+    render: function() {
+        const BaseDialog = sdk.getComponent('views.dialogs.BaseDialog');
+        const DialogButtons = sdk.getComponent('views.elements.DialogButtons');
+        const Spinner = sdk.getComponent('views.elements.Spinner');
+
+        let buttons;
+        if (this.state.busy) {
+            buttons = <Spinner />;
+        } else {
+            buttons = <DialogButtons
+                primaryButton={_t(
+                    'Upgrade this room to version %(version)s',
+                    {version: this._targetVersion},
+                )}
+                primaryButtonClass="danger"
+                hasCancel={true}
+                onPrimaryButtonClick={this._onUpgradeClick}
+                focus={this.props.focus}
+                onCancel={this._onCancelClick}
+            />;
+        }
+
+        return (
+            <BaseDialog className="mx_RoomUpgradeDialog"
+                onFinished={this.onCancelled}
+                title={_t("Upgrade Room Version")}
+                contentId='mx_Dialog_content'
+                onFinished={this.props.onFinished}
+                hasCancel={true}
+            >
+                <p>
+                    {_t(
+                        "Upgrading this room requires closing down the current " +
+                        "instance of the room and creating a new room it its place. " +
+                        "To give room members the best possible experience, we will:",
+                    )}
+                </p>
+                <ol>
+                    <li>{_t("Create a new room with the same name, description and avatar")}</li>
+                    <li>{_t("Update any local room aliases to point to the new room")}</li>
+                    <li>{_t("Stop users from speaking in the old version of the room, and post a message advising users to move to the new room")}</li>
+                    <li>{_t("Put a link back to the old room at the start of the new room so people can see old messages")}</li>
+                </ol>
+                {buttons}
+            </BaseDialog>
+        );
+    },
+});
diff --git a/src/components/views/rooms/RoomSettings.js b/src/components/views/rooms/RoomSettings.js
index 7a78d205b9..aeb55be075 100644
--- a/src/components/views/rooms/RoomSettings.js
+++ b/src/components/views/rooms/RoomSettings.js
@@ -572,6 +572,11 @@ module.exports = React.createClass({
         });
     },
 
+    _onRoomUpgradeClick: function() {
+        const RoomUpgradeDialog = sdk.getComponent('dialogs.RoomUpgradeDialog');
+        Modal.createTrackedDialog('Upgrade Room Version', '', RoomUpgradeDialog, {room: this.props.room});
+    },
+
     _onRoomMemberMembership: function() {
         // Update, since our banned user list may have changed
         this.forceUpdate();
@@ -930,6 +935,13 @@ module.exports = React.createClass({
             );
         });
 
+        let roomUpgradeButton = null;
+        if (this.props.room.shouldUpgradeToVersion() && this.props.room.userMayUpgradeRoom(myUserId)) {
+            roomUpgradeButton = <AccessibleButton className="mx_RoomSettings_upgradeButton danger" onClick={this._onRoomUpgradeClick}>
+                { _t("Upgrade room to version %(ver)s", {ver: this.props.room.shouldUpgradeToVersion()}) }
+            </AccessibleButton>;
+        }
+
         return (
             <div className="mx_RoomSettings">
 
@@ -1041,7 +1053,8 @@ module.exports = React.createClass({
                 <h3>{ _t('Advanced') }</h3>
                 <div className="mx_RoomSettings_settings">
                     { _t('Internal room ID: ') } <code>{ this.props.room.roomId }</code><br />
-                    { _t('Room version number: ') } <code>{ this.props.room.getVersion() }</code>
+                    { _t('Room version number: ') } <code>{ this.props.room.getVersion() }</code><br />
+                    { roomUpgradeButton }
                 </div>
             </div>
         );
diff --git a/src/components/views/rooms/RoomUpgradeWarningBar.js b/src/components/views/rooms/RoomUpgradeWarningBar.js
new file mode 100644
index 0000000000..a464d95140
--- /dev/null
+++ b/src/components/views/rooms/RoomUpgradeWarningBar.js
@@ -0,0 +1,57 @@
+/*
+Copyright 2018 New Vector Ltd
+
+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 sdk from '../../../index';
+import Modal from '../../../Modal';
+
+import { _t } from '../../../languageHandler';
+
+module.exports = React.createClass({
+    displayName: 'RoomUpgardeWarningBar',
+
+    propTypes: {
+        room: PropTypes.object.isRequired,
+    },
+
+    onUpgradeClick: function() {
+        const RoomUpgradeDialog = sdk.getComponent('dialogs.RoomUpgradeDialog');
+        Modal.createTrackedDialog('Upgrade Room Version', '', RoomUpgradeDialog, {room: this.props.room});
+    },
+
+    render: function() {
+        const AccessibleButton = sdk.getComponent('elements.AccessibleButton');
+        return (
+            <div className="mx_RoomUpgradeWarningBar">
+                <div className="mx_RoomUpgradeWarningBar_header">
+                    {_t("There is a known vulnerability affecting this room.")}
+                </div>
+                <div className="mx_RoomUpgradeWarningBar_body">
+                    {_t("This room version is vulnerable to malicious modification of room state.")}
+                </div>
+                <p className="mx_RoomUpgradeWarningBar_upgradelink">
+                    <AccessibleButton onClick={this.onUpgradeClick}>
+                        {_t("Click here to upgrade to the latest room version and ensure room integrity is protected.")}
+                    </AccessibleButton>
+                </p>
+                <div className="mx_RoomUpgradeWarningBar_small">
+                    {_t("Only room administrators will see this warning")}
+                </div>
+            </div>
+        );
+    },
+});
diff --git a/src/i18n/strings/en_EN.json b/src/i18n/strings/en_EN.json
index fcc9bcc8be..043b90518d 100644
--- a/src/i18n/strings/en_EN.json
+++ b/src/i18n/strings/en_EN.json
@@ -205,6 +205,7 @@
     "Authentication check failed: incorrect password?": "Authentication check failed: incorrect password?",
     "Failed to join room": "Failed to join room",
     "Message Pinning": "Message Pinning",
+    "Increase performance by only loading room members on first view": "Increase performance by only loading room members on first view",
     "Disable Emoji suggestions while typing": "Disable Emoji suggestions while typing",
     "Use compact timeline layout": "Use compact timeline layout",
     "Hide removed messages": "Hide removed messages",
@@ -528,6 +529,7 @@
     "Guests cannot join this room even if explicitly invited.": "Guests cannot join this room even if explicitly invited.",
     "Click here to fix": "Click here to fix",
     "To send events of type <eventType/>, you must be a": "To send events of type <eventType/>, you must be a",
+    "Upgrade room to version %(ver)s": "Upgrade room to version %(ver)s",
     "Who can access this room?": "Who can access this room?",
     "Only people who have been invited": "Only people who have been invited",
     "Anyone who knows the room's link, apart from guests": "Anyone who knows the room's link, apart from guests",
@@ -865,6 +867,9 @@
     "Ignore request": "Ignore request",
     "Loading device info...": "Loading device info...",
     "Encryption key request": "Encryption key request",
+    "Failed to upgrade room": "Failed to upgrade room",
+    "The room upgrade could not be completed": "The room upgrade could not be completed",
+    "Upgrade this room to version %(version)s": "Upgrade this room to version %(version)s",
     "Upgrade Room Version": "Upgrade Room Version",
     "Upgrading this room requires closing down the current instance of the room and creating a new room it its place. To give room members the best possible experience, we will:": "Upgrading this room requires closing down the current instance of the room and creating a new room it its place. To give room members the best possible experience, we will:",
     "Create a new room with the same name, description and avatar": "Create a new room with the same name, description and avatar",
@@ -1121,6 +1126,8 @@
     "Labs": "Labs",
     "These are experimental features that may break in unexpected ways": "These are experimental features that may break in unexpected ways",
     "Use with caution": "Use with caution",
+    "Lazy loading members not supported": "Lazy loading members not supported",
+    "Lazy loading is not supported by your current homeserver.": "Lazy loading is not supported by your current homeserver.",
     "Deactivate my account": "Deactivate my account",
     "Clear Cache": "Clear Cache",
     "Clear Cache and Reload": "Clear Cache and Reload",
@@ -1231,8 +1238,5 @@
     "Import": "Import",
     "Failed to set direct chat tag": "Failed to set direct chat tag",
     "Failed to remove tag %(tagName)s from room": "Failed to remove tag %(tagName)s from room",
-    "Failed to add tag %(tagName)s to room": "Failed to add tag %(tagName)s to room",
-    "Increase performance by only loading room members on first view": "Increase performance by only loading room members on first view",
-    "Lazy loading members not supported": "Lazy load members not supported",
-    "Lazy loading is not supported by your current homeserver.": "Lazy loading is not supported by your current homeserver."
+    "Failed to add tag %(tagName)s to room": "Failed to add tag %(tagName)s to room"
 }