diff --git a/src/components/views/rooms/MessageComposerInput.js b/src/components/views/rooms/MessageComposerInput.js
index 818c108211..01e836765a 100644
--- a/src/components/views/rooms/MessageComposerInput.js
+++ b/src/components/views/rooms/MessageComposerInput.js
@@ -43,6 +43,8 @@ import Markdown from '../../../Markdown';
 import ComposerHistoryManager from '../../../ComposerHistoryManager';
 import {onSendMessageFailed} from './MessageComposerInputOld';
 
+import MessageComposerStore from '../../../stores/MessageComposerStore';
+
 const TYPING_USER_TIMEOUT = 10000, TYPING_SERVER_TIMEOUT = 30000;
 
 const ZWS_CODE = 8203;
@@ -170,6 +172,11 @@ export default class MessageComposerInput extends React.Component {
     componentDidMount() {
         this.dispatcherRef = dis.register(this.onAction);
         this.historyManager = new ComposerHistoryManager(this.props.room.roomId);
+
+        // Reinstate the editor state for this room
+        this.setState({
+            editorState: MessageComposerStore.getEditorState(this.props.room.roomId),
+        });
     }
 
     componentWillUnmount() {
@@ -336,6 +343,14 @@ export default class MessageComposerInput extends React.Component {
                 this.onFinishedTyping();
             }
 
+            // Record the editor state for this room so that it can be retrieved after
+            // switching to another room and back
+            dis.dispatch({
+                action: 'editor_state',
+                room_id: this.props.room.roomId,
+                editor_state: state.editorState,
+            });
+
             if (!state.hasOwnProperty('originalEditorState')) {
                 state.originalEditorState = null;
             }
@@ -632,6 +647,10 @@ export default class MessageComposerInput extends React.Component {
     };
 
     onVerticalArrow = (e, up) => {
+        if (e.ctrlKey || e.shiftKey || e.altKey || e.metaKey) {
+            return;
+        }
+
         // Select history only if we are not currently auto-completing
         if (this.autocomplete.state.completionList.length === 0) {
             // Don't go back in history if we're in the middle of a multi-line message
diff --git a/src/stores/MessageComposerStore.js b/src/stores/MessageComposerStore.js
new file mode 100644
index 0000000000..1e83105300
--- /dev/null
+++ b/src/stores/MessageComposerStore.js
@@ -0,0 +1,73 @@
+/*
+Copyright 2017 Vector Creations 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 dis from '../dispatcher';
+import {Store} from 'flux/utils';
+
+const INITIAL_STATE = {
+    editorStateMap: {},
+};
+
+/**
+ * A class for storing application state to do with the message composer. This is a simple
+ * flux store that listens for actions and updates its state accordingly, informing any
+ * listeners (views) of state changes.
+ */
+class MessageComposerStore extends Store {
+    constructor() {
+        super(dis);
+
+        // Initialise state
+        this._state = INITIAL_STATE;
+    }
+
+    _setState(newState) {
+        this._state = Object.assign(this._state, newState);
+        this.__emitChange();
+    }
+
+    __onDispatch(payload) {
+        switch (payload.action) {
+            case 'editor_state':
+                this._editorState(payload);
+                break;
+            case 'on_logged_out':
+                this.reset();
+                break;
+        }
+    }
+
+    _editorState(payload) {
+        const editorStateMap = this._state.editorStateMap;
+        editorStateMap[payload.room_id] = payload.editor_state;
+        this._setState({
+            editorStateMap: editorStateMap,
+        });
+    }
+
+    getEditorState(roomId) {
+        return this._state.editorStateMap[roomId];
+    }
+
+    reset() {
+        this._state = Object.assign({}, INITIAL_STATE);
+    }
+}
+
+let singletonMessageComposerStore = null;
+if (!singletonMessageComposerStore) {
+    singletonMessageComposerStore = new MessageComposerStore();
+}
+module.exports = singletonMessageComposerStore;