diff --git a/src/ContentMessages.js b/src/ContentMessages.js
index dab8de2465..2d58622db8 100644
--- a/src/ContentMessages.js
+++ b/src/ContentMessages.js
@@ -59,38 +59,40 @@ export class UploadCanceledError extends Error {}
  *  and a thumbnail key.
  */
 function createThumbnail(element, inputWidth, inputHeight, mimeType) {
-    return new Promise((resolve) => {
-        let targetWidth = inputWidth;
-        let targetHeight = inputHeight;
-        if (targetHeight > MAX_HEIGHT) {
-            targetWidth = Math.floor(targetWidth * (MAX_HEIGHT / targetHeight));
-            targetHeight = MAX_HEIGHT;
-        }
-        if (targetWidth > MAX_WIDTH) {
-            targetHeight = Math.floor(targetHeight * (MAX_WIDTH / targetWidth));
-            targetWidth = MAX_WIDTH;
-        }
+    const deferred = Promise.defer();
 
-        const canvas = document.createElement("canvas");
-        canvas.width = targetWidth;
-        canvas.height = targetHeight;
-        canvas.getContext("2d").drawImage(element, 0, 0, targetWidth, targetHeight);
-        canvas.toBlob(function(thumbnail) {
-            resolve({
-                info: {
-                    thumbnail_info: {
-                        w: targetWidth,
-                        h: targetHeight,
-                        mimetype: thumbnail.type,
-                        size: thumbnail.size,
-                    },
-                    w: inputWidth,
-                    h: inputHeight,
+    let targetWidth = inputWidth;
+    let targetHeight = inputHeight;
+    if (targetHeight > MAX_HEIGHT) {
+        targetWidth = Math.floor(targetWidth * (MAX_HEIGHT / targetHeight));
+        targetHeight = MAX_HEIGHT;
+    }
+    if (targetWidth > MAX_WIDTH) {
+        targetHeight = Math.floor(targetHeight * (MAX_WIDTH / targetWidth));
+        targetWidth = MAX_WIDTH;
+    }
+
+    const canvas = document.createElement("canvas");
+    canvas.width = targetWidth;
+    canvas.height = targetHeight;
+    canvas.getContext("2d").drawImage(element, 0, 0, targetWidth, targetHeight);
+    canvas.toBlob(function(thumbnail) {
+        deferred.resolve({
+            info: {
+                thumbnail_info: {
+                    w: targetWidth,
+                    h: targetHeight,
+                    mimetype: thumbnail.type,
+                    size: thumbnail.size,
                 },
-                thumbnail: thumbnail,
-            });
-        }, mimeType);
-    });
+                w: inputWidth,
+                h: inputHeight,
+            },
+            thumbnail: thumbnail,
+        });
+    }, mimeType);
+
+    return deferred.promise;
 }
 
 /**
@@ -177,29 +179,30 @@ function infoForImageFile(matrixClient, roomId, imageFile) {
  * @return {Promise} A promise that resolves with the video image element.
  */
 function loadVideoElement(videoFile) {
-    return new Promise((resolve, reject) => {
-        // Load the file into an html element
-        const video = document.createElement("video");
+    const deferred = Promise.defer();
 
-        const reader = new FileReader();
+    // Load the file into an html element
+    const video = document.createElement("video");
 
-        reader.onload = function(e) {
-            video.src = e.target.result;
+    const reader = new FileReader();
+    reader.onload = function(e) {
+        video.src = e.target.result;
 
-            // Once ready, returns its size
-            // Wait until we have enough data to thumbnail the first frame.
-            video.onloadeddata = function() {
-                resolve(video);
-            };
-            video.onerror = function(e) {
-                reject(e);
-            };
+        // Once ready, returns its size
+        // Wait until we have enough data to thumbnail the first frame.
+        video.onloadeddata = function() {
+            deferred.resolve(video);
         };
-        reader.onerror = function(e) {
-            reject(e);
+        video.onerror = function(e) {
+            deferred.reject(e);
         };
-        reader.readAsDataURL(videoFile);
-    });
+    };
+    reader.onerror = function(e) {
+        deferred.reject(e);
+    };
+    reader.readAsDataURL(videoFile);
+
+    return deferred.promise;
 }
 
 /**
@@ -233,16 +236,16 @@ function infoForVideoFile(matrixClient, roomId, videoFile) {
  *   is read.
  */
 function readFileAsArrayBuffer(file) {
-    return new Promise((resolve, reject) => {
-        const reader = new FileReader();
-        reader.onload = function(e) {
-            resolve(e.target.result);
-        };
-        reader.onerror = function(e) {
-            reject(e);
-        };
-        reader.readAsArrayBuffer(file);
-    });
+    const deferred = Promise.defer();
+    const reader = new FileReader();
+    reader.onload = function(e) {
+        deferred.resolve(e.target.result);
+    };
+    reader.onerror = function(e) {
+        deferred.reject(e);
+    };
+    reader.readAsArrayBuffer(file);
+    return deferred.promise;
 }
 
 /**
@@ -458,34 +461,33 @@ export default class ContentMessages {
             content.info.mimetype = file.type;
         }
 
-        const prom = new Promise((resolve) => {
-            if (file.type.indexOf('image/') == 0) {
-                content.msgtype = 'm.image';
-                infoForImageFile(matrixClient, roomId, file).then((imageInfo)=>{
-                    extend(content.info, imageInfo);
-                    resolve();
-                }, (error)=>{
-                    console.error(error);
-                    content.msgtype = 'm.file';
-                    resolve();
-                });
-            } else if (file.type.indexOf('audio/') == 0) {
-                content.msgtype = 'm.audio';
-                resolve();
-            } else if (file.type.indexOf('video/') == 0) {
-                content.msgtype = 'm.video';
-                infoForVideoFile(matrixClient, roomId, file).then((videoInfo)=>{
-                    extend(content.info, videoInfo);
-                    resolve();
-                }, (error)=>{
-                    content.msgtype = 'm.file';
-                    resolve();
-                });
-            } else {
+        const def = Promise.defer();
+        if (file.type.indexOf('image/') == 0) {
+            content.msgtype = 'm.image';
+            infoForImageFile(matrixClient, roomId, file).then((imageInfo)=>{
+                extend(content.info, imageInfo);
+                def.resolve();
+            }, (error)=>{
+                console.error(error);
                 content.msgtype = 'm.file';
-                resolve();
-            }
-        });
+                def.resolve();
+            });
+        } else if (file.type.indexOf('audio/') == 0) {
+            content.msgtype = 'm.audio';
+            def.resolve();
+        } else if (file.type.indexOf('video/') == 0) {
+            content.msgtype = 'm.video';
+            infoForVideoFile(matrixClient, roomId, file).then((videoInfo)=>{
+                extend(content.info, videoInfo);
+                def.resolve();
+            }, (error)=>{
+                content.msgtype = 'm.file';
+                def.resolve();
+            });
+        } else {
+            content.msgtype = 'm.file';
+            def.resolve();
+        }
 
         const upload = {
             fileName: file.name || 'Attachment',
@@ -507,7 +509,7 @@ export default class ContentMessages {
             dis.dispatch({action: 'upload_progress', upload: upload});
         }
 
-        return prom.then(function() {
+        return def.promise.then(function() {
             // XXX: upload.promise must be the promise that
             // is returned by uploadFile as it has an abort()
             // method hacked onto it.
diff --git a/src/Lifecycle.js b/src/Lifecycle.js
index 53a9b7a998..13f3abccb1 100644
--- a/src/Lifecycle.js
+++ b/src/Lifecycle.js
@@ -312,14 +312,18 @@ async function _restoreFromLocalStorage(opts) {
 function _handleLoadSessionFailure(e) {
     console.error("Unable to load session", e);
 
+    const def = Promise.defer();
     const SessionRestoreErrorDialog =
           sdk.getComponent('views.dialogs.SessionRestoreErrorDialog');
 
-    const modal = Modal.createTrackedDialog('Session Restore Error', '', SessionRestoreErrorDialog, {
+    Modal.createTrackedDialog('Session Restore Error', '', SessionRestoreErrorDialog, {
         error: e.message,
+        onFinished: (success) => {
+            def.resolve(success);
+        },
     });
 
-    return modal.finished.then(([success]) => {
+    return def.promise.then((success) => {
         if (success) {
             // user clicked continue.
             _clearStorage();
diff --git a/src/components/views/rooms/Autocomplete.js b/src/components/views/rooms/Autocomplete.js
index d4b51081f4..ad5fa198a3 100644
--- a/src/components/views/rooms/Autocomplete.js
+++ b/src/components/views/rooms/Autocomplete.js
@@ -26,7 +26,6 @@ import { Room } from 'matrix-js-sdk';
 
 import SettingsStore from "../../../settings/SettingsStore";
 import Autocompleter from '../../../autocomplete/Autocompleter';
-import {sleep} from "../../../utils/promise";
 
 const COMPOSER_SELECTED = 0;
 
@@ -106,11 +105,13 @@ export default class Autocomplete extends React.Component {
             autocompleteDelay = 0;
         }
 
-        return new Promise((resolve) => {
-            this.debounceCompletionsRequest = setTimeout(() => {
-                resolve(this.processQuery(query, selection));
-            }, autocompleteDelay);
-        });
+        const deferred = Promise.defer();
+        this.debounceCompletionsRequest = setTimeout(() => {
+            this.processQuery(query, selection).then(() => {
+                deferred.resolve();
+            });
+        }, autocompleteDelay);
+        return deferred.promise;
     }
 
     processQuery(query, selection) {
@@ -196,16 +197,16 @@ export default class Autocomplete extends React.Component {
     }
 
     forceComplete() {
-        return new Promise((resolve) => {
-            this.setState({
-                forceComplete: true,
-                hide: false,
-            }, () => {
-                this.complete(this.props.query, this.props.selection).then(() => {
-                    resolve(this.countCompletions());
-                });
+        const done = Promise.defer();
+        this.setState({
+            forceComplete: true,
+            hide: false,
+        }, () => {
+            this.complete(this.props.query, this.props.selection).then(() => {
+                done.resolve(this.countCompletions());
             });
         });
+        return done.promise;
     }
 
     onCompletionClicked(selectionOffset: number): boolean {
diff --git a/src/components/views/settings/ChangePassword.js b/src/components/views/settings/ChangePassword.js
index 91292b19f9..a086efaa6d 100644
--- a/src/components/views/settings/ChangePassword.js
+++ b/src/components/views/settings/ChangePassword.js
@@ -178,12 +178,17 @@ module.exports = createReactClass({
     },
 
     _optionallySetEmail: function() {
+        const deferred = Promise.defer();
         // Ask for an email otherwise the user has no way to reset their password
         const SetEmailDialog = sdk.getComponent("dialogs.SetEmailDialog");
-        const modal = Modal.createTrackedDialog('Do you want to set an email address?', '', SetEmailDialog, {
+        Modal.createTrackedDialog('Do you want to set an email address?', '', SetEmailDialog, {
             title: _t('Do you want to set an email address?'),
+            onFinished: (confirmed) => {
+                // ignore confirmed, setting an email is optional
+                deferred.resolve(confirmed);
+            },
         });
-        return modal.finished.then(([confirmed]) => confirmed);
+        return deferred.promise;
     },
 
     _onExportE2eKeysClicked: function() {
diff --git a/src/rageshake/submit-rageshake.js b/src/rageshake/submit-rageshake.js
index e772912e48..99c412a6ab 100644
--- a/src/rageshake/submit-rageshake.js
+++ b/src/rageshake/submit-rageshake.js
@@ -105,22 +105,26 @@ export default async function sendBugReport(bugReportEndpoint, opts) {
 }
 
 function _submitReport(endpoint, body, progressCallback) {
-    return new Promise((resolve, reject) => {
-        const req = new XMLHttpRequest();
-        req.open("POST", endpoint);
-        req.timeout = 5 * 60 * 1000;
-        req.onreadystatechange = function() {
-            if (req.readyState === XMLHttpRequest.LOADING) {
-                progressCallback(_t("Waiting for response from server"));
-            } else if (req.readyState === XMLHttpRequest.DONE) {
-                // on done
-                if (req.status < 200 || req.status >= 400) {
-                    reject(new Error(`HTTP ${req.status}`));
-                    return;
-                }
-                resolve();
-            }
-        };
-        req.send(body);
-    });
+    const deferred = Promise.defer();
+
+    const req = new XMLHttpRequest();
+    req.open("POST", endpoint);
+    req.timeout = 5 * 60 * 1000;
+    req.onreadystatechange = function() {
+        if (req.readyState === XMLHttpRequest.LOADING) {
+            progressCallback(_t("Waiting for response from server"));
+        } else if (req.readyState === XMLHttpRequest.DONE) {
+            on_done();
+        }
+    };
+    req.send(body);
+    return deferred.promise;
+
+    function on_done() {
+        if (req.status < 200 || req.status >= 400) {
+            deferred.reject(new Error(`HTTP ${req.status}`));
+            return;
+        }
+        deferred.resolve();
+    }
 }