diff --git a/src/CallHandler.tsx b/src/CallHandler.tsx
index 6e1e6ce83a..a0adee6b8d 100644
--- a/src/CallHandler.tsx
+++ b/src/CallHandler.tsx
@@ -154,7 +154,7 @@ export default class CallHandler extends EventEmitter {
     private supportsPstnProtocol = null;
     private pstnSupportPrefixed = null; // True if the server only support the prefixed pstn protocol
     private supportsSipNativeVirtual = null; // im.vector.protocol.sip_virtual and im.vector.protocol.sip_native
-    private pstnSupportCheckTimer: NodeJS.Timeout; // number actually because we're in the browser
+    private pstnSupportCheckTimer: number;
     // For rooms we've been invited to, true if they're from virtual user, false if we've checked and they aren't.
     private invitedRoomsAreVirtual = new Map<string, boolean>();
     private invitedRoomCheckInProgress = false;
diff --git a/src/ContentMessages.tsx b/src/ContentMessages.tsx
index 0ab193081b..b752886b8a 100644
--- a/src/ContentMessages.tsx
+++ b/src/ContentMessages.tsx
@@ -39,7 +39,7 @@ import {
     UploadStartedPayload,
 } from "./dispatcher/payloads/UploadPayload";
 import { IUpload } from "./models/IUpload";
-import { IImageInfo } from "matrix-js-sdk/src/@types/partials";
+import { IAbortablePromise, IImageInfo } from "matrix-js-sdk/src/@types/partials";
 
 const MAX_WIDTH = 800;
 const MAX_HEIGHT = 600;
@@ -85,10 +85,6 @@ interface IThumbnail {
     thumbnail: Blob;
 }
 
-interface IAbortablePromise<T> extends Promise<T> {
-    abort(): void;
-}
-
 /**
  * Create a thumbnail for a image DOM element.
  * The image will be smaller than MAX_WIDTH and MAX_HEIGHT.
@@ -333,7 +329,7 @@ export function uploadFile(
     roomId: string,
     file: File | Blob,
     progressHandler?: any, // TODO: Types
-): Promise<{url?: string, file?: any}> { // TODO: Types
+): IAbortablePromise<{url?: string, file?: any}> { // TODO: Types
     let canceled = false;
     if (matrixClient.isRoomEncrypted(roomId)) {
         // If the room is encrypted then encrypt the file before uploading it.
@@ -365,8 +361,8 @@ export function uploadFile(
                 encryptInfo.mimetype = file.type;
             }
             return { "file": encryptInfo };
-        });
-        (prom as IAbortablePromise<any>).abort = () => {
+        }) as IAbortablePromise<{ file: any }>;
+        prom.abort = () => {
             canceled = true;
             if (uploadPromise) matrixClient.cancelUpload(uploadPromise);
         };
@@ -379,8 +375,8 @@ export function uploadFile(
             if (canceled) throw new UploadCanceledError();
             // If the attachment isn't encrypted then include the URL directly.
             return { url };
-        });
-        (promise1 as any).abort = () => {
+        }) as IAbortablePromise<{ url: string }>;
+        promise1.abort = () => {
             canceled = true;
             matrixClient.cancelUpload(basePromise);
         };
@@ -551,10 +547,10 @@ export default class ContentMessages {
                 content.msgtype = 'm.file';
                 resolve();
             }
-        });
+        }) as IAbortablePromise<void>;
 
         // create temporary abort handler for before the actual upload gets passed off to js-sdk
-        (prom as IAbortablePromise<any>).abort = () => {
+        prom.abort = () => {
             upload.canceled = true;
         };
 
@@ -583,9 +579,7 @@ export default class ContentMessages {
             // XXX: upload.promise must be the promise that
             // is returned by uploadFile as it has an abort()
             // method hacked onto it.
-            upload.promise = uploadFile(
-                matrixClient, roomId, file, onProgress,
-            );
+            upload.promise = uploadFile(matrixClient, roomId, file, onProgress);
             return upload.promise.then(function(result) {
                 content.file = result.file;
                 content.url = result.url;
diff --git a/src/CountlyAnalytics.ts b/src/CountlyAnalytics.ts
index a75c578536..72b0462bcd 100644
--- a/src/CountlyAnalytics.ts
+++ b/src/CountlyAnalytics.ts
@@ -364,8 +364,8 @@ export default class CountlyAnalytics {
 
     private initTime = CountlyAnalytics.getTimestamp();
     private firstPage = true;
-    private heartbeatIntervalId: NodeJS.Timeout;
-    private activityIntervalId: NodeJS.Timeout;
+    private heartbeatIntervalId: number;
+    private activityIntervalId: number;
     private trackTime = true;
     private lastBeat: number;
     private storedDuration = 0;
diff --git a/src/DecryptionFailureTracker.ts b/src/DecryptionFailureTracker.ts
index d40574a6db..df306a54f5 100644
--- a/src/DecryptionFailureTracker.ts
+++ b/src/DecryptionFailureTracker.ts
@@ -46,8 +46,8 @@ export class DecryptionFailureTracker {
     };
 
     // Set to an interval ID when `start` is called
-    public checkInterval: NodeJS.Timeout = null;
-    public trackInterval: NodeJS.Timeout = null;
+    public checkInterval: number = null;
+    public trackInterval: number = null;
 
     // Spread the load on `Analytics` by tracking at a low frequency, `TRACK_INTERVAL_MS`.
     static TRACK_INTERVAL_MS = 60000;
diff --git a/src/MatrixClientPeg.ts b/src/MatrixClientPeg.ts
index 063c5f4cad..7de62ba075 100644
--- a/src/MatrixClientPeg.ts
+++ b/src/MatrixClientPeg.ts
@@ -17,8 +17,8 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import { ICreateClientOpts } from 'matrix-js-sdk/src/matrix';
-import { MatrixClient } from 'matrix-js-sdk/src/client';
+import { ICreateClientOpts, PendingEventOrdering } from 'matrix-js-sdk/src/matrix';
+import { IStartClientOpts, MatrixClient } from 'matrix-js-sdk/src/client';
 import { MemoryStore } from 'matrix-js-sdk/src/store/memory';
 import * as utils from 'matrix-js-sdk/src/utils';
 import { EventTimeline } from 'matrix-js-sdk/src/models/event-timeline';
@@ -47,16 +47,8 @@ export interface IMatrixClientCreds {
     freshLogin?: boolean;
 }
 
-// TODO: Move this to the js-sdk
-export interface IOpts {
-    initialSyncLimit?: number;
-    pendingEventOrdering?: "detached" | "chronological";
-    lazyLoadMembers?: boolean;
-    clientWellKnownPollPeriod?: number;
-}
-
 export interface IMatrixClientPeg {
-    opts: IOpts;
+    opts: IStartClientOpts;
 
     /**
      * Sets the script href passed to the IndexedDB web worker
@@ -127,7 +119,7 @@ class _MatrixClientPeg implements IMatrixClientPeg {
     // client is started in 'start'. These can be altered
     // at any time up to after the 'will_start_client'
     // event is finished processing.
-    public opts: IOpts = {
+    public opts: IStartClientOpts = {
         initialSyncLimit: 20,
     };
 
@@ -231,7 +223,7 @@ class _MatrixClientPeg implements IMatrixClientPeg {
 
         const opts = utils.deepCopy(this.opts);
         // the react sdk doesn't work without this, so don't allow
-        opts.pendingEventOrdering = "detached";
+        opts.pendingEventOrdering = PendingEventOrdering.Detached;
         opts.lazyLoadMembers = true;
         opts.clientWellKnownPollPeriod = 2 * 60 * 60; // 2 hours
 
diff --git a/src/Rooms.ts b/src/Rooms.ts
index b27d00e804..6e2fd4d3a2 100644
--- a/src/Rooms.ts
+++ b/src/Rooms.ts
@@ -84,10 +84,8 @@ export function guessAndSetDMRoom(room: Room, isDirect: boolean): Promise<void>
                    this room as a DM room
  * @returns {object} A promise
  */
-export function setDMRoom(roomId: string, userId: string): Promise<void> {
-    if (MatrixClientPeg.get().isGuest()) {
-        return Promise.resolve();
-    }
+export async function setDMRoom(roomId: string, userId: string): Promise<void> {
+    if (MatrixClientPeg.get().isGuest()) return;
 
     const mDirectEvent = MatrixClientPeg.get().getAccountData('m.direct');
     let dmRoomMap = {};
@@ -116,7 +114,7 @@ export function setDMRoom(roomId: string, userId: string): Promise<void> {
         dmRoomMap[userId] = roomList;
     }
 
-    return MatrixClientPeg.get().setAccountData('m.direct', dmRoomMap);
+    await MatrixClientPeg.get().setAccountData('m.direct', dmRoomMap);
 }
 
 /**
diff --git a/src/Searching.js b/src/Searching.ts
similarity index 79%
rename from src/Searching.js
rename to src/Searching.ts
index d0666b1760..37f85efa77 100644
--- a/src/Searching.js
+++ b/src/Searching.ts
@@ -1,5 +1,5 @@
 /*
-Copyright 2019 The Matrix.org Foundation C.I.C.
+Copyright 2019 - 2021 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.
@@ -14,26 +14,42 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import {
+    IResultRoomEvents,
+    ISearchRequestBody,
+    ISearchResponse,
+    ISearchResult,
+    ISearchResults,
+    SearchOrderBy,
+} from "matrix-js-sdk/src/@types/search";
+import { IRoomEventFilter } from "matrix-js-sdk/src/filter";
+import { EventType } from "matrix-js-sdk/src/@types/event";
+
+import { ISearchArgs } from "./indexing/BaseEventIndexManager";
 import EventIndexPeg from "./indexing/EventIndexPeg";
 import { MatrixClientPeg } from "./MatrixClientPeg";
+import { SearchResult } from "matrix-js-sdk/src/models/search-result";
 
 const SEARCH_LIMIT = 10;
 
-async function serverSideSearch(term, roomId = undefined) {
+async function serverSideSearch(
+    term: string,
+    roomId: string = undefined,
+): Promise<{ response: ISearchResponse, query: ISearchRequestBody }> {
     const client = MatrixClientPeg.get();
 
-    const filter = {
+    const filter: IRoomEventFilter = {
         limit: SEARCH_LIMIT,
     };
 
     if (roomId !== undefined) filter.rooms = [roomId];
 
-    const body = {
+    const body: ISearchRequestBody = {
         search_categories: {
             room_events: {
                 search_term: term,
                 filter: filter,
-                order_by: "recent",
+                order_by: SearchOrderBy.Recent,
                 event_context: {
                     before_limit: 1,
                     after_limit: 1,
@@ -45,31 +61,26 @@ async function serverSideSearch(term, roomId = undefined) {
 
     const response = await client.search({ body: body });
 
-    const result = {
-        response: response,
-        query: body,
-    };
-
-    return result;
+    return { response, query: body };
 }
 
-async function serverSideSearchProcess(term, roomId = undefined) {
+async function serverSideSearchProcess(term: string, roomId: string = undefined): Promise<ISearchResults> {
     const client = MatrixClientPeg.get();
     const result = await serverSideSearch(term, roomId);
 
     // The js-sdk method backPaginateRoomEventsSearch() uses _query internally
-    // so we're reusing the concept here since we wan't to delegate the
+    // so we're reusing the concept here since we want to delegate the
     // pagination back to backPaginateRoomEventsSearch() in some cases.
-    const searchResult = {
+    const searchResults: ISearchResults = {
         _query: result.query,
         results: [],
         highlights: [],
     };
 
-    return client.processRoomEventsSearch(searchResult, result.response);
+    return client.processRoomEventsSearch(searchResults, result.response);
 }
 
-function compareEvents(a, b) {
+function compareEvents(a: ISearchResult, b: ISearchResult): number {
     const aEvent = a.result;
     const bEvent = b.result;
 
@@ -79,7 +90,7 @@ function compareEvents(a, b) {
     return 0;
 }
 
-async function combinedSearch(searchTerm) {
+async function combinedSearch(searchTerm: string): Promise<ISearchResults> {
     const client = MatrixClientPeg.get();
 
     // Create two promises, one for the local search, one for the
@@ -111,10 +122,10 @@ async function combinedSearch(searchTerm) {
     // returns since that one can be either a server-side one, a local one or a
     // fake one to fetch the remaining cached events. See the docs for
     // combineEvents() for an explanation why we need to cache events.
-    const emptyResult = {
+    const emptyResult: ISeshatSearchResults = {
         seshatQuery: localQuery,
         _query: serverQuery,
-        serverSideNextBatch: serverResponse.next_batch,
+        serverSideNextBatch: serverResponse.search_categories.room_events.next_batch,
         cachedEvents: [],
         oldestEventFrom: "server",
         results: [],
@@ -125,7 +136,7 @@ async function combinedSearch(searchTerm) {
     const combinedResult = combineResponses(emptyResult, localResponse, serverResponse.search_categories.room_events);
 
     // Let the client process the combined result.
-    const response = {
+    const response: ISearchResponse = {
         search_categories: {
             room_events: combinedResult,
         },
@@ -139,10 +150,14 @@ async function combinedSearch(searchTerm) {
     return result;
 }
 
-async function localSearch(searchTerm, roomId = undefined, processResult = true) {
+async function localSearch(
+    searchTerm: string,
+    roomId: string = undefined,
+    processResult = true,
+): Promise<{ response: IResultRoomEvents, query: ISearchArgs }> {
     const eventIndex = EventIndexPeg.get();
 
-    const searchArgs = {
+    const searchArgs: ISearchArgs = {
         search_term: searchTerm,
         before_limit: 1,
         after_limit: 1,
@@ -167,11 +182,18 @@ async function localSearch(searchTerm, roomId = undefined, processResult = true)
     return result;
 }
 
-async function localSearchProcess(searchTerm, roomId = undefined) {
+export interface ISeshatSearchResults extends ISearchResults {
+    seshatQuery?: ISearchArgs;
+    cachedEvents?: ISearchResult[];
+    oldestEventFrom?: "local" | "server";
+    serverSideNextBatch?: string;
+}
+
+async function localSearchProcess(searchTerm: string, roomId: string = undefined): Promise<ISeshatSearchResults> {
     const emptyResult = {
         results: [],
         highlights: [],
-    };
+    } as ISeshatSearchResults;
 
     if (searchTerm === "") return emptyResult;
 
@@ -179,7 +201,7 @@ async function localSearchProcess(searchTerm, roomId = undefined) {
 
     emptyResult.seshatQuery = result.query;
 
-    const response = {
+    const response: ISearchResponse = {
         search_categories: {
             room_events: result.response,
         },
@@ -192,7 +214,7 @@ async function localSearchProcess(searchTerm, roomId = undefined) {
     return processedResult;
 }
 
-async function localPagination(searchResult) {
+async function localPagination(searchResult: ISeshatSearchResults): Promise<ISeshatSearchResults> {
     const eventIndex = EventIndexPeg.get();
 
     const searchArgs = searchResult.seshatQuery;
@@ -221,10 +243,10 @@ async function localPagination(searchResult) {
     return result;
 }
 
-function compareOldestEvents(firstResults, secondResults) {
+function compareOldestEvents(firstResults: ISearchResult[], secondResults: ISearchResult[]): number {
     try {
-        const oldestFirstEvent = firstResults.results[firstResults.results.length - 1].result;
-        const oldestSecondEvent = secondResults.results[secondResults.results.length - 1].result;
+        const oldestFirstEvent = firstResults[firstResults.length - 1].result;
+        const oldestSecondEvent = secondResults[secondResults.length - 1].result;
 
         if (oldestFirstEvent.origin_server_ts <= oldestSecondEvent.origin_server_ts) {
             return -1;
@@ -236,7 +258,12 @@ function compareOldestEvents(firstResults, secondResults) {
     }
 }
 
-function combineEventSources(previousSearchResult, response, a, b) {
+function combineEventSources(
+    previousSearchResult: ISeshatSearchResults,
+    response: IResultRoomEvents,
+    a: ISearchResult[],
+    b: ISearchResult[],
+): void {
     // Merge event sources and sort the events.
     const combinedEvents = a.concat(b).sort(compareEvents);
     // Put half of the events in the response, and cache the other half.
@@ -353,8 +380,12 @@ function combineEventSources(previousSearchResult, response, a, b) {
  * different event sources.
  *
  */
-function combineEvents(previousSearchResult, localEvents = undefined, serverEvents = undefined) {
-    const response = {};
+function combineEvents(
+    previousSearchResult: ISeshatSearchResults,
+    localEvents: IResultRoomEvents = undefined,
+    serverEvents: IResultRoomEvents = undefined,
+): IResultRoomEvents {
+    const response = {} as IResultRoomEvents;
 
     const cachedEvents = previousSearchResult.cachedEvents;
     let oldestEventFrom = previousSearchResult.oldestEventFrom;
@@ -364,7 +395,7 @@ function combineEvents(previousSearchResult, localEvents = undefined, serverEven
         // This is a first search call, combine the events from the server and
         // the local index. Note where our oldest event came from, we shall
         // fetch the next batch of events from the other source.
-        if (compareOldestEvents(localEvents, serverEvents) < 0) {
+        if (compareOldestEvents(localEvents.results, serverEvents.results) < 0) {
             oldestEventFrom = "local";
         }
 
@@ -375,7 +406,7 @@ function combineEvents(previousSearchResult, localEvents = undefined, serverEven
         // meaning that our oldest event was on the server.
         // Change the source of the oldest event if our local event is older
         // than the cached one.
-        if (compareOldestEvents(localEvents, cachedEvents) < 0) {
+        if (compareOldestEvents(localEvents.results, cachedEvents) < 0) {
             oldestEventFrom = "local";
         }
         combineEventSources(previousSearchResult, response, localEvents.results, cachedEvents);
@@ -384,7 +415,7 @@ function combineEvents(previousSearchResult, localEvents = undefined, serverEven
         // meaning that our oldest event was in the local index.
         // Change the source of the oldest event if our server event is older
         // than the cached one.
-        if (compareOldestEvents(serverEvents, cachedEvents) < 0) {
+        if (compareOldestEvents(serverEvents.results, cachedEvents) < 0) {
             oldestEventFrom = "server";
         }
         combineEventSources(previousSearchResult, response, serverEvents.results, cachedEvents);
@@ -412,7 +443,11 @@ function combineEvents(previousSearchResult, localEvents = undefined, serverEven
  * @return {object} A response object that combines the events from the
  * different event sources.
  */
-function combineResponses(previousSearchResult, localEvents = undefined, serverEvents = undefined) {
+function combineResponses(
+    previousSearchResult: ISeshatSearchResults,
+    localEvents: IResultRoomEvents = undefined,
+    serverEvents: IResultRoomEvents = undefined,
+): IResultRoomEvents {
     // Combine our events first.
     const response = combineEvents(previousSearchResult, localEvents, serverEvents);
 
@@ -454,42 +489,51 @@ function combineResponses(previousSearchResult, localEvents = undefined, serverE
     return response;
 }
 
-function restoreEncryptionInfo(searchResultSlice = []) {
+interface IEncryptedSeshatEvent {
+    curve25519Key: string;
+    ed25519Key: string;
+    algorithm: string;
+    forwardingCurve25519KeyChain: string[];
+}
+
+function restoreEncryptionInfo(searchResultSlice: SearchResult[] = []): void {
     for (let i = 0; i < searchResultSlice.length; i++) {
         const timeline = searchResultSlice[i].context.getTimeline();
 
         for (let j = 0; j < timeline.length; j++) {
-            const ev = timeline[j];
+            const mxEv = timeline[j];
+            const ev = mxEv.event as IEncryptedSeshatEvent;
 
-            if (ev.event.curve25519Key) {
-                ev.makeEncrypted(
-                    "m.room.encrypted",
-                    { algorithm: ev.event.algorithm },
-                    ev.event.curve25519Key,
-                    ev.event.ed25519Key,
+            if (ev.curve25519Key) {
+                mxEv.makeEncrypted(
+                    EventType.RoomMessageEncrypted,
+                    { algorithm: ev.algorithm },
+                    ev.curve25519Key,
+                    ev.ed25519Key,
                 );
-                ev.forwardingCurve25519KeyChain = ev.event.forwardingCurve25519KeyChain;
+                // @ts-ignore
+                mxEv.forwardingCurve25519KeyChain = ev.forwardingCurve25519KeyChain;
 
-                delete ev.event.curve25519Key;
-                delete ev.event.ed25519Key;
-                delete ev.event.algorithm;
-                delete ev.event.forwardingCurve25519KeyChain;
+                delete ev.curve25519Key;
+                delete ev.ed25519Key;
+                delete ev.algorithm;
+                delete ev.forwardingCurve25519KeyChain;
             }
         }
     }
 }
 
-async function combinedPagination(searchResult) {
+async function combinedPagination(searchResult: ISeshatSearchResults): Promise<ISeshatSearchResults> {
     const eventIndex = EventIndexPeg.get();
     const client = MatrixClientPeg.get();
 
     const searchArgs = searchResult.seshatQuery;
     const oldestEventFrom = searchResult.oldestEventFrom;
 
-    let localResult;
-    let serverSideResult;
+    let localResult: IResultRoomEvents;
+    let serverSideResult: ISearchResponse;
 
-    // Fetch events from the local index if we have a token for itand if it's
+    // Fetch events from the local index if we have a token for it and if it's
     // the local indexes turn or the server has exhausted its results.
     if (searchArgs.next_batch && (!searchResult.serverSideNextBatch || oldestEventFrom === "server")) {
         localResult = await eventIndex.search(searchArgs);
@@ -502,7 +546,7 @@ async function combinedPagination(searchResult) {
         serverSideResult = await client.search(body);
     }
 
-    let serverEvents;
+    let serverEvents: IResultRoomEvents;
 
     if (serverSideResult) {
         serverEvents = serverSideResult.search_categories.room_events;
@@ -532,8 +576,8 @@ async function combinedPagination(searchResult) {
     return result;
 }
 
-function eventIndexSearch(term, roomId = undefined) {
-    let searchPromise;
+function eventIndexSearch(term: string, roomId: string = undefined): Promise<ISearchResults> {
+    let searchPromise: Promise<ISearchResults>;
 
     if (roomId !== undefined) {
         if (MatrixClientPeg.get().isRoomEncrypted(roomId)) {
@@ -554,7 +598,7 @@ function eventIndexSearch(term, roomId = undefined) {
     return searchPromise;
 }
 
-function eventIndexSearchPagination(searchResult) {
+function eventIndexSearchPagination(searchResult: ISeshatSearchResults): Promise<ISeshatSearchResults> {
     const client = MatrixClientPeg.get();
 
     const seshatQuery = searchResult.seshatQuery;
@@ -580,7 +624,7 @@ function eventIndexSearchPagination(searchResult) {
     }
 }
 
-export function searchPagination(searchResult) {
+export function searchPagination(searchResult: ISearchResults): Promise<ISearchResults> {
     const eventIndex = EventIndexPeg.get();
     const client = MatrixClientPeg.get();
 
@@ -590,7 +634,7 @@ export function searchPagination(searchResult) {
     else return eventIndexSearchPagination(searchResult);
 }
 
-export default function eventSearch(term, roomId = undefined) {
+export default function eventSearch(term: string, roomId: string = undefined): Promise<ISearchResults> {
     const eventIndex = EventIndexPeg.get();
 
     if (eventIndex === null) return serverSideSearchProcess(term, roomId);
diff --git a/src/components/structures/MatrixChat.tsx b/src/components/structures/MatrixChat.tsx
index d692b0fa7f..aa31a9faf4 100644
--- a/src/components/structures/MatrixChat.tsx
+++ b/src/components/structures/MatrixChat.tsx
@@ -251,7 +251,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     private pageChanging: boolean;
     private tokenLogin?: boolean;
     private accountPassword?: string;
-    private accountPasswordTimer?: NodeJS.Timeout;
+    private accountPasswordTimer?: number;
     private focusComposer: boolean;
     private subTitleStatus: string;
     private prevWindowWidth: number;
diff --git a/src/components/structures/RoomDirectory.tsx b/src/components/structures/RoomDirectory.tsx
index b1974d6c0a..aa5baaf8c2 100644
--- a/src/components/structures/RoomDirectory.tsx
+++ b/src/components/structures/RoomDirectory.tsx
@@ -16,6 +16,9 @@ limitations under the License.
 */
 
 import React from "react";
+import { IFieldType, IInstance, IProtocol, IPublicRoomsChunkRoom } from "matrix-js-sdk/src/client";
+import { Visibility } from "matrix-js-sdk/src/@types/partials";
+import { IRoomDirectoryOptions } from "matrix-js-sdk/src/@types/requests";
 
 import { MatrixClientPeg } from "../../MatrixClientPeg";
 import dis from "../../dispatcher/dispatcher";
@@ -25,7 +28,7 @@ import { _t } from '../../languageHandler';
 import SdkConfig from '../../SdkConfig';
 import { instanceForInstanceId, protocolNameForInstanceId } from '../../utils/DirectoryUtils';
 import Analytics from '../../Analytics';
-import { ALL_ROOMS, IFieldType, IInstance, IProtocol, Protocols } from "../views/directory/NetworkDropdown";
+import NetworkDropdown, { ALL_ROOMS, Protocols } from "../views/directory/NetworkDropdown";
 import SettingsStore from "../../settings/SettingsStore";
 import GroupFilterOrderStore from "../../stores/GroupFilterOrderStore";
 import GroupStore from "../../stores/GroupStore";
@@ -40,7 +43,6 @@ import ErrorDialog from "../views/dialogs/ErrorDialog";
 import QuestionDialog from "../views/dialogs/QuestionDialog";
 import BaseDialog from "../views/dialogs/BaseDialog";
 import DirectorySearchBox from "../views/elements/DirectorySearchBox";
-import NetworkDropdown from "../views/directory/NetworkDropdown";
 import ScrollPanel from "./ScrollPanel";
 import Spinner from "../views/elements/Spinner";
 import { ActionPayload } from "../../dispatcher/payloads";
@@ -61,7 +63,7 @@ interface IProps extends IDialogProps {
 }
 
 interface IState {
-    publicRooms: IRoom[];
+    publicRooms: IPublicRoomsChunkRoom[];
     loading: boolean;
     protocolsLoading: boolean;
     error?: string;
@@ -72,35 +74,12 @@ interface IState {
     communityName?: string;
 }
 
-/* eslint-disable camelcase */
-interface IRoom {
-    room_id: string;
-    name?: string;
-    avatar_url?: string;
-    topic?: string;
-    canonical_alias?: string;
-    aliases?: string[];
-    world_readable: boolean;
-    guest_can_join: boolean;
-    num_joined_members: number;
-}
-
-interface IPublicRoomsRequest {
-    limit?: number;
-    since?: string;
-    server?: string;
-    filter?: object;
-    include_all_networks?: boolean;
-    third_party_instance_id?: string;
-}
-/* eslint-enable camelcase */
-
 @replaceableComponent("structures.RoomDirectory")
 export default class RoomDirectory extends React.Component<IProps, IState> {
     private readonly startTime: number;
     private unmounted = false;
     private nextBatch: string = null;
-    private filterTimeout: NodeJS.Timeout;
+    private filterTimeout: number;
     private protocols: Protocols;
 
     constructor(props) {
@@ -253,7 +232,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
         // remember the next batch token when we sent the request
         // too. If it's changed, appending to the list will corrupt it.
         const nextBatch = this.nextBatch;
-        const opts: IPublicRoomsRequest = { limit: 20 };
+        const opts: IRoomDirectoryOptions = { limit: 20 };
         if (roomServer != MatrixClientPeg.getHomeserverName()) {
             opts.server = roomServer;
         }
@@ -326,7 +305,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
      * HS admins to do this through the RoomSettings interface, but
      * this needs SPEC-417.
      */
-    private removeFromDirectory(room: IRoom) {
+    private removeFromDirectory(room: IPublicRoomsChunkRoom) {
         const alias = getDisplayAliasForRoom(room);
         const name = room.name || alias || _t('Unnamed room');
 
@@ -346,7 +325,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
                 const modal = Modal.createDialog(Spinner);
                 let step = _t('remove %(name)s from the directory.', { name: name });
 
-                MatrixClientPeg.get().setRoomDirectoryVisibility(room.room_id, 'private').then(() => {
+                MatrixClientPeg.get().setRoomDirectoryVisibility(room.room_id, Visibility.Private).then(() => {
                     if (!alias) return;
                     step = _t('delete the address.');
                     return MatrixClientPeg.get().deleteAlias(alias);
@@ -368,7 +347,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
         });
     }
 
-    private onRoomClicked = (room: IRoom, ev: ButtonEvent) => {
+    private onRoomClicked = (room: IPublicRoomsChunkRoom, ev: ButtonEvent) => {
         // If room was shift-clicked, remove it from the room directory
         if (ev.shiftKey && !this.state.selectedCommunityId) {
             ev.preventDefault();
@@ -481,17 +460,17 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
         }
     };
 
-    private onPreviewClick = (ev: ButtonEvent, room: IRoom) => {
+    private onPreviewClick = (ev: ButtonEvent, room: IPublicRoomsChunkRoom) => {
         this.showRoom(room, null, false, true);
         ev.stopPropagation();
     };
 
-    private onViewClick = (ev: ButtonEvent, room: IRoom) => {
+    private onViewClick = (ev: ButtonEvent, room: IPublicRoomsChunkRoom) => {
         this.showRoom(room);
         ev.stopPropagation();
     };
 
-    private onJoinClick = (ev: ButtonEvent, room: IRoom) => {
+    private onJoinClick = (ev: ButtonEvent, room: IPublicRoomsChunkRoom) => {
         this.showRoom(room, null, true);
         ev.stopPropagation();
     };
@@ -509,7 +488,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
         this.showRoom(null, alias, autoJoin);
     }
 
-    private showRoom(room: IRoom, roomAlias?: string, autoJoin = false, shouldPeek = false) {
+    private showRoom(room: IPublicRoomsChunkRoom, roomAlias?: string, autoJoin = false, shouldPeek = false) {
         this.onFinished();
         const payload: ActionPayload = {
             action: 'view_room',
@@ -558,7 +537,7 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
         dis.dispatch(payload);
     }
 
-    private createRoomCells(room: IRoom) {
+    private createRoomCells(room: IPublicRoomsChunkRoom) {
         const client = MatrixClientPeg.get();
         const clientRoom = client.getRoom(room.room_id);
         const hasJoinedRoom = clientRoom && clientRoom.getMyMembership() === "join";
@@ -854,6 +833,6 @@ export default class RoomDirectory extends React.Component<IProps, IState> {
 
 // Similar to matrix-react-sdk's MatrixTools.getDisplayAliasForRoom
 // but works with the objects we get from the public room list
-function getDisplayAliasForRoom(room: IRoom) {
+function getDisplayAliasForRoom(room: IPublicRoomsChunkRoom) {
     return getDisplayAliasForAliasSet(room.canonical_alias, room.aliases);
 }
diff --git a/src/components/structures/RoomView.tsx b/src/components/structures/RoomView.tsx
index 8e0b8a5f4a..2c118149a0 100644
--- a/src/components/structures/RoomView.tsx
+++ b/src/components/structures/RoomView.tsx
@@ -25,8 +25,8 @@ import React, { createRef } from 'react';
 import classNames from 'classnames';
 import { IRecommendedVersion, NotificationCountType, Room } from "matrix-js-sdk/src/models/room";
 import { MatrixEvent } from "matrix-js-sdk/src/models/event";
-import { SearchResult } from "matrix-js-sdk/src/models/search-result";
 import { EventSubscription } from "fbemitter";
+import { ISearchResults } from 'matrix-js-sdk/src/@types/search';
 
 import shouldHideEvent from '../../shouldHideEvent';
 import { _t } from '../../languageHandler';
@@ -133,12 +133,7 @@ export interface IState {
     searching: boolean;
     searchTerm?: string;
     searchScope?: SearchScope;
-    searchResults?: XOR<{}, {
-        count: number;
-        highlights: string[];
-        results: SearchResult[];
-        next_batch: string; // eslint-disable-line camelcase
-    }>;
+    searchResults?: XOR<{}, ISearchResults>;
     searchHighlights?: string[];
     searchInProgress?: boolean;
     callState?: CallState;
@@ -1137,7 +1132,7 @@ export default class RoomView extends React.Component<IProps, IState> {
 
         if (this.state.searchResults.next_batch) {
             debuglog("requesting more search results");
-            const searchPromise = searchPagination(this.state.searchResults);
+            const searchPromise = searchPagination(this.state.searchResults as ISearchResults);
             return this.handleSearchResult(searchPromise);
         } else {
             debuglog("no more search results");
diff --git a/src/components/structures/ScrollPanel.tsx b/src/components/structures/ScrollPanel.tsx
index df885575df..1d16755106 100644
--- a/src/components/structures/ScrollPanel.tsx
+++ b/src/components/structures/ScrollPanel.tsx
@@ -187,7 +187,7 @@ export default class ScrollPanel extends React.Component<IProps> {
     private fillRequestWhileRunning: boolean;
     private scrollState: IScrollState;
     private preventShrinkingState: IPreventShrinkingState;
-    private unfillDebouncer: NodeJS.Timeout;
+    private unfillDebouncer: number;
     private bottomGrowth: number;
     private pages: number;
     private heightUpdateInProgress: boolean;
diff --git a/src/components/structures/SpaceRoomDirectory.tsx b/src/components/structures/SpaceRoomDirectory.tsx
index a08fbb5098..27539a5c3c 100644
--- a/src/components/structures/SpaceRoomDirectory.tsx
+++ b/src/components/structures/SpaceRoomDirectory.tsx
@@ -18,6 +18,7 @@ import React, { ReactNode, useMemo, useState } from "react";
 import { Room } from "matrix-js-sdk/src/models/room";
 import { MatrixClient } from "matrix-js-sdk/src/client";
 import { EventType, RoomType } from "matrix-js-sdk/src/@types/event";
+import { ISpaceSummaryRoom, ISpaceSummaryEvent } from "matrix-js-sdk/src/@types/spaces";
 import classNames from "classnames";
 import { sortBy } from "lodash";
 
@@ -52,36 +53,6 @@ interface IHierarchyProps {
     showRoom(room: ISpaceSummaryRoom, viaServers?: string[], autoJoin?: boolean): void;
 }
 
-/* eslint-disable camelcase */
-export interface ISpaceSummaryRoom {
-    canonical_alias?: string;
-    aliases: string[];
-    avatar_url?: string;
-    guest_can_join: boolean;
-    name?: string;
-    num_joined_members: number;
-    room_id: string;
-    topic?: string;
-    world_readable: boolean;
-    num_refs: number;
-    room_type: string;
-}
-
-export interface ISpaceSummaryEvent {
-    room_id: string;
-    event_id: string;
-    origin_server_ts: number;
-    type: string;
-    state_key: string;
-    content: {
-        order?: string;
-        suggested?: boolean;
-        auto_join?: boolean;
-        via?: string[];
-    };
-}
-/* eslint-enable camelcase */
-
 interface ITileProps {
     room: ISpaceSummaryRoom;
     suggested?: boolean;
diff --git a/src/components/views/dialogs/InviteDialog.tsx b/src/components/views/dialogs/InviteDialog.tsx
index 1df5f35ae9..c9475d4849 100644
--- a/src/components/views/dialogs/InviteDialog.tsx
+++ b/src/components/views/dialogs/InviteDialog.tsx
@@ -109,11 +109,11 @@ export abstract class Member {
 
 class DirectoryMember extends Member {
     private readonly _userId: string;
-    private readonly displayName: string;
-    private readonly avatarUrl: string;
+    private readonly displayName?: string;
+    private readonly avatarUrl?: string;
 
     // eslint-disable-next-line camelcase
-    constructor(userDirResult: { user_id: string, display_name: string, avatar_url: string }) {
+    constructor(userDirResult: { user_id: string, display_name?: string, avatar_url?: string }) {
         super();
         this._userId = userDirResult.user_id;
         this.displayName = userDirResult.display_name;
@@ -370,7 +370,7 @@ export default class InviteDialog extends React.PureComponent<IInviteDialogProps
     };
 
     private closeCopiedTooltip: () => void;
-    private debounceTimer: NodeJS.Timeout = null; // actually number because we're in the browser
+    private debounceTimer: number = null; // actually number because we're in the browser
     private editorRef = createRef<HTMLInputElement>();
     private unmounted = false;
 
diff --git a/src/components/views/directory/NetworkDropdown.tsx b/src/components/views/directory/NetworkDropdown.tsx
index 0492168f36..e4a967fbdc 100644
--- a/src/components/views/directory/NetworkDropdown.tsx
+++ b/src/components/views/directory/NetworkDropdown.tsx
@@ -17,6 +17,7 @@ limitations under the License.
 
 import React, { useEffect, useState } from "react";
 import { MatrixError } from "matrix-js-sdk/src/http-api";
+import { IProtocol } from "matrix-js-sdk/src/client";
 
 import { MatrixClientPeg } from '../../../MatrixClientPeg';
 import { instanceForInstanceId } from '../../../utils/DirectoryUtils';
@@ -83,30 +84,6 @@ const validServer = withValidation<undefined, { error?: MatrixError }>({
     ],
 });
 
-/* eslint-disable camelcase */
-export interface IFieldType {
-    regexp: string;
-    placeholder: string;
-}
-
-export interface IInstance {
-    desc: string;
-    icon?: string;
-    fields: object;
-    network_id: string;
-    // XXX: this is undocumented but we rely on it.
-    instance_id: string;
-}
-
-export interface IProtocol {
-    user_fields: string[];
-    location_fields: string[];
-    icon: string;
-    field_types: Record<string, IFieldType>;
-    instances: IInstance[];
-}
-/* eslint-enable camelcase */
-
 export type Protocols = Record<string, IProtocol>;
 
 interface IProps {
diff --git a/src/components/views/elements/MiniAvatarUploader.tsx b/src/components/views/elements/MiniAvatarUploader.tsx
index 83fc1ebefd..47bcd845ba 100644
--- a/src/components/views/elements/MiniAvatarUploader.tsx
+++ b/src/components/views/elements/MiniAvatarUploader.tsx
@@ -32,7 +32,7 @@ interface IProps {
     hasAvatar: boolean;
     noAvatarLabel?: string;
     hasAvatarLabel?: string;
-    setAvatarUrl(url: string): Promise<void>;
+    setAvatarUrl(url: string): Promise<unknown>;
 }
 
 const MiniAvatarUploader: React.FC<IProps> = ({ hasAvatar, hasAvatarLabel, noAvatarLabel, setAvatarUrl, children }) => {
diff --git a/src/components/views/room_settings/RoomPublishSetting.tsx b/src/components/views/room_settings/RoomPublishSetting.tsx
index 5b6858abf5..1cc83dea9e 100644
--- a/src/components/views/room_settings/RoomPublishSetting.tsx
+++ b/src/components/views/room_settings/RoomPublishSetting.tsx
@@ -15,6 +15,7 @@ limitations under the License.
 */
 
 import React from "react";
+import { Visibility } from "matrix-js-sdk/src/@types/partials";
 
 import LabelledToggleSwitch from "../elements/LabelledToggleSwitch";
 import { _t } from "../../../languageHandler";
@@ -50,7 +51,7 @@ export default class RoomPublishSetting extends React.PureComponent<IProps, ISta
 
         client.setRoomDirectoryVisibility(
             this.props.roomId,
-            newValue ? 'public' : 'private',
+            newValue ? Visibility.Public : Visibility.Private,
         ).catch(() => {
             // Roll back the local echo on the change
             this.setState({ isRoomPublished: valueBefore });
diff --git a/src/components/views/rooms/Autocomplete.tsx b/src/components/views/rooms/Autocomplete.tsx
index 8fbecbe722..6b5edcf91b 100644
--- a/src/components/views/rooms/Autocomplete.tsx
+++ b/src/components/views/rooms/Autocomplete.tsx
@@ -55,7 +55,7 @@ interface IState {
 export default class Autocomplete extends React.PureComponent<IProps, IState> {
     autocompleter: Autocompleter;
     queryRequested: string;
-    debounceCompletionsRequest: NodeJS.Timeout;
+    debounceCompletionsRequest: number;
     private containerRef = createRef<HTMLDivElement>();
 
     constructor(props) {
diff --git a/src/components/views/settings/tabs/user/AppearanceUserSettingsTab.tsx b/src/components/views/settings/tabs/user/AppearanceUserSettingsTab.tsx
index f04c2f13ae..17aa9e5561 100644
--- a/src/components/views/settings/tabs/user/AppearanceUserSettingsTab.tsx
+++ b/src/components/views/settings/tabs/user/AppearanceUserSettingsTab.tsx
@@ -75,7 +75,7 @@ interface IState extends IThemeState {
 export default class AppearanceUserSettingsTab extends React.Component<IProps, IState> {
     private readonly MESSAGE_PREVIEW_TEXT = _t("Hey you. You're the best!");
 
-    private themeTimer: NodeJS.Timeout;
+    private themeTimer: number;
 
     constructor(props: IProps) {
         super(props);
diff --git a/src/components/views/spaces/SpaceSettingsVisibilityTab.tsx b/src/components/views/spaces/SpaceSettingsVisibilityTab.tsx
index f27b73a511..b76d53be41 100644
--- a/src/components/views/spaces/SpaceSettingsVisibilityTab.tsx
+++ b/src/components/views/spaces/SpaceSettingsVisibilityTab.tsx
@@ -39,7 +39,7 @@ enum SpaceVisibility {
 
 const useLocalEcho = <T extends any>(
     currentFactory: () => T,
-    setterFn: (value: T) => Promise<void>,
+    setterFn: (value: T) => Promise<unknown>,
     errorFn: (error: Error) => void,
 ): [value: T, handler: (value: T) => void] => {
     const [value, setValue] = useState(currentFactory);
diff --git a/src/components/views/toasts/VerificationRequestToast.tsx b/src/components/views/toasts/VerificationRequestToast.tsx
index 75254d7c62..45f1464b0e 100644
--- a/src/components/views/toasts/VerificationRequestToast.tsx
+++ b/src/components/views/toasts/VerificationRequestToast.tsx
@@ -44,7 +44,7 @@ interface IState {
 
 @replaceableComponent("views.toasts.VerificationRequestToast")
 export default class VerificationRequestToast extends React.PureComponent<IProps, IState> {
-    private intervalHandle: NodeJS.Timeout;
+    private intervalHandle: number;
 
     constructor(props) {
         super(props);
diff --git a/src/indexing/BaseEventIndexManager.ts b/src/indexing/BaseEventIndexManager.ts
index 4bae3e7c1d..64576e4412 100644
--- a/src/indexing/BaseEventIndexManager.ts
+++ b/src/indexing/BaseEventIndexManager.ts
@@ -14,47 +14,16 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { IMatrixProfile, IEventWithRoomId as IMatrixEvent, IResultRoomEvents } from "matrix-js-sdk/src/@types/search";
+import { Direction } from "matrix-js-sdk/src";
+
 // The following interfaces take their names and member names from seshat and the spec
 /* eslint-disable camelcase */
-
-export interface IMatrixEvent {
-    type: string;
-    sender: string;
-    content: {};
-    event_id: string;
-    origin_server_ts: number;
-    unsigned?: {};
-    roomId: string;
-}
-
-export interface IMatrixProfile {
-    avatar_url: string;
-    displayname: string;
-}
-
 export interface ICrawlerCheckpoint {
     roomId: string;
     token: string;
     fullCrawl?: boolean;
-    direction: string;
-}
-
-export interface IResultContext {
-    events_before: [IMatrixEvent];
-    events_after: [IMatrixEvent];
-    profile_info: Map<string, IMatrixProfile>;
-}
-
-export interface IResultsElement {
-    rank: number;
-    result: IMatrixEvent;
-    context: IResultContext;
-}
-
-export interface ISearchResult {
-    count: number;
-    results: [IResultsElement];
-    highlights: [string];
+    direction: Direction;
 }
 
 export interface ISearchArgs {
@@ -63,6 +32,8 @@ export interface ISearchArgs {
     after_limit: number;
     order_by_recency: boolean;
     room_id?: string;
+    limit: number;
+    next_batch?: string;
 }
 
 export interface IEventAndProfile {
@@ -205,10 +176,10 @@ export default abstract class BaseEventIndexManager {
      * @param {ISearchArgs} searchArgs The search configuration for the search,
      * sets the search term and determines the search result contents.
      *
-     * @return {Promise<[ISearchResult]>} A promise that will resolve to an array
+     * @return {Promise<IResultRoomEvents[]>} A promise that will resolve to an array
      * of search results once the search is done.
      */
-    async searchEventIndex(searchArgs: ISearchArgs): Promise<ISearchResult> {
+    async searchEventIndex(searchArgs: ISearchArgs): Promise<IResultRoomEvents> {
         throw new Error("Unimplemented");
     }
 
diff --git a/src/indexing/EventIndex.ts b/src/indexing/EventIndex.ts
index 76104455f7..a5827fc599 100644
--- a/src/indexing/EventIndex.ts
+++ b/src/indexing/EventIndex.ts
@@ -23,6 +23,7 @@ import { EventTimelineSet } from 'matrix-js-sdk/src/models/event-timeline-set';
 import { RoomState } from 'matrix-js-sdk/src/models/room-state';
 import { TimelineWindow } from 'matrix-js-sdk/src/timeline-window';
 import { sleep } from "matrix-js-sdk/src/utils";
+import { IResultRoomEvents } from "matrix-js-sdk/src/@types/search";
 
 import PlatformPeg from "../PlatformPeg";
 import { MatrixClientPeg } from "../MatrixClientPeg";
@@ -114,14 +115,14 @@ export default class EventIndex extends EventEmitter {
             const backCheckpoint: ICrawlerCheckpoint = {
                 roomId: room.roomId,
                 token: token,
-                direction: "b",
+                direction: Direction.Backward,
                 fullCrawl: true,
             };
 
             const forwardCheckpoint: ICrawlerCheckpoint = {
                 roomId: room.roomId,
                 token: token,
-                direction: "f",
+                direction: Direction.Forward,
             };
 
             try {
@@ -384,7 +385,7 @@ export default class EventIndex extends EventEmitter {
             roomId: room.roomId,
             token: token,
             fullCrawl: fullCrawl,
-            direction: "b",
+            direction: Direction.Backward,
         };
 
         console.log("EventIndex: Adding checkpoint", checkpoint);
@@ -671,10 +672,10 @@ export default class EventIndex extends EventEmitter {
      * @param {ISearchArgs} searchArgs The search configuration for the search,
      * sets the search term and determines the search result contents.
      *
-     * @return {Promise<[SearchResult]>} A promise that will resolve to an array
+     * @return {Promise<IResultRoomEvents[]>} A promise that will resolve to an array
      * of search results once the search is done.
      */
-    public async search(searchArgs: ISearchArgs) {
+    public async search(searchArgs: ISearchArgs): Promise<IResultRoomEvents> {
         const indexManager = PlatformPeg.get().getEventIndexingManager();
         return indexManager.searchEventIndex(searchArgs);
     }
diff --git a/src/models/IUpload.ts b/src/models/IUpload.ts
index 5b376e9330..1b5a13e394 100644
--- a/src/models/IUpload.ts
+++ b/src/models/IUpload.ts
@@ -14,11 +14,13 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { IAbortablePromise } from "matrix-js-sdk/src/@types/partials";
+
 export interface IUpload {
     fileName: string;
     roomId: string;
     total: number;
     loaded: number;
-    promise: Promise<any>;
+    promise: IAbortablePromise<any>;
     canceled?: boolean;
 }
diff --git a/src/settings/handlers/AccountSettingsHandler.ts b/src/settings/handlers/AccountSettingsHandler.ts
index 60ec849883..9c937ebd88 100644
--- a/src/settings/handlers/AccountSettingsHandler.ts
+++ b/src/settings/handlers/AccountSettingsHandler.ts
@@ -123,12 +123,13 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
         return preferredValue;
     }
 
-    public setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
+    public async setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
         // Special case URL previews
         if (settingName === "urlPreviewsEnabled") {
             const content = this.getSettings("org.matrix.preview_urls") || {};
             content['disable'] = !newValue;
-            return MatrixClientPeg.get().setAccountData("org.matrix.preview_urls", content);
+            await MatrixClientPeg.get().setAccountData("org.matrix.preview_urls", content);
+            return;
         }
 
         // Special case for breadcrumbs
@@ -141,26 +142,29 @@ export default class AccountSettingsHandler extends MatrixClientBackedSettingsHa
             if (!content) content = {}; // If we still don't have content, make some
 
             content['recent_rooms'] = newValue;
-            return MatrixClientPeg.get().setAccountData(BREADCRUMBS_EVENT_TYPE, content);
+            await MatrixClientPeg.get().setAccountData(BREADCRUMBS_EVENT_TYPE, content);
+            return;
         }
 
         // Special case recent emoji
         if (settingName === "recent_emoji") {
             const content = this.getSettings(RECENT_EMOJI_EVENT_TYPE) || {};
             content["recent_emoji"] = newValue;
-            return MatrixClientPeg.get().setAccountData(RECENT_EMOJI_EVENT_TYPE, content);
+            await MatrixClientPeg.get().setAccountData(RECENT_EMOJI_EVENT_TYPE, content);
+            return;
         }
 
         // Special case integration manager provisioning
         if (settingName === "integrationProvisioning") {
             const content = this.getSettings(INTEG_PROVISIONING_EVENT_TYPE) || {};
             content['enabled'] = newValue;
-            return MatrixClientPeg.get().setAccountData(INTEG_PROVISIONING_EVENT_TYPE, content);
+            await MatrixClientPeg.get().setAccountData(INTEG_PROVISIONING_EVENT_TYPE, content);
+            return;
         }
 
         const content = this.getSettings() || {};
         content[settingName] = newValue;
-        return MatrixClientPeg.get().setAccountData("im.vector.web.settings", content);
+        await MatrixClientPeg.get().setAccountData("im.vector.web.settings", content);
     }
 
     public canSetValue(settingName: string, roomId: string): boolean {
diff --git a/src/settings/handlers/RoomAccountSettingsHandler.ts b/src/settings/handlers/RoomAccountSettingsHandler.ts
index e0345fde8c..a5ebfae621 100644
--- a/src/settings/handlers/RoomAccountSettingsHandler.ts
+++ b/src/settings/handlers/RoomAccountSettingsHandler.ts
@@ -86,22 +86,24 @@ export default class RoomAccountSettingsHandler extends MatrixClientBackedSettin
         return settings[settingName];
     }
 
-    public setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
+    public async setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
         // Special case URL previews
         if (settingName === "urlPreviewsEnabled") {
             const content = this.getSettings(roomId, "org.matrix.room.preview_urls") || {};
             content['disable'] = !newValue;
-            return MatrixClientPeg.get().setRoomAccountData(roomId, "org.matrix.room.preview_urls", content);
+            await MatrixClientPeg.get().setRoomAccountData(roomId, "org.matrix.room.preview_urls", content);
+            return;
         }
 
         // Special case allowed widgets
         if (settingName === "allowedWidgets") {
-            return MatrixClientPeg.get().setRoomAccountData(roomId, ALLOWED_WIDGETS_EVENT_TYPE, newValue);
+            await MatrixClientPeg.get().setRoomAccountData(roomId, ALLOWED_WIDGETS_EVENT_TYPE, newValue);
+            return;
         }
 
         const content = this.getSettings(roomId) || {};
         content[settingName] = newValue;
-        return MatrixClientPeg.get().setRoomAccountData(roomId, "im.vector.web.settings", content);
+        await MatrixClientPeg.get().setRoomAccountData(roomId, "im.vector.web.settings", content);
     }
 
     public canSetValue(settingName: string, roomId: string): boolean {
diff --git a/src/settings/handlers/RoomSettingsHandler.ts b/src/settings/handlers/RoomSettingsHandler.ts
index 3315e40a65..974f94062c 100644
--- a/src/settings/handlers/RoomSettingsHandler.ts
+++ b/src/settings/handlers/RoomSettingsHandler.ts
@@ -87,17 +87,18 @@ export default class RoomSettingsHandler extends MatrixClientBackedSettingsHandl
         return settings[settingName];
     }
 
-    public setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
+    public async setValue(settingName: string, roomId: string, newValue: any): Promise<void> {
         // Special case URL previews
         if (settingName === "urlPreviewsEnabled") {
             const content = this.getSettings(roomId, "org.matrix.room.preview_urls") || {};
             content['disable'] = !newValue;
-            return MatrixClientPeg.get().sendStateEvent(roomId, "org.matrix.room.preview_urls", content);
+            await MatrixClientPeg.get().sendStateEvent(roomId, "org.matrix.room.preview_urls", content);
+            return;
         }
 
         const content = this.getSettings(roomId) || {};
         content[settingName] = newValue;
-        return MatrixClientPeg.get().sendStateEvent(roomId, "im.vector.web.settings", content, "");
+        await MatrixClientPeg.get().sendStateEvent(roomId, "im.vector.web.settings", content, "");
     }
 
     public canSetValue(settingName: string, roomId: string): boolean {
diff --git a/src/stores/SpaceStore.tsx b/src/stores/SpaceStore.tsx
index 6300c1a936..99705a7aba 100644
--- a/src/stores/SpaceStore.tsx
+++ b/src/stores/SpaceStore.tsx
@@ -18,6 +18,7 @@ import { ListIteratee, Many, sortBy, throttle } from "lodash";
 import { EventType, RoomType } from "matrix-js-sdk/src/@types/event";
 import { Room } from "matrix-js-sdk/src/models/room";
 import { MatrixEvent } from "matrix-js-sdk/src/models/event";
+import { ISpaceSummaryRoom } from "matrix-js-sdk/src/@types/spaces";
 
 import { AsyncStoreWithClient } from "./AsyncStoreWithClient";
 import defaultDispatcher from "../dispatcher/dispatcher";
@@ -31,7 +32,6 @@ import { RoomNotificationStateStore } from "./notifications/RoomNotificationStat
 import { DefaultTagID } from "./room-list/models";
 import { EnhancedMap, mapDiff } from "../utils/maps";
 import { setHasDiff } from "../utils/sets";
-import { ISpaceSummaryEvent, ISpaceSummaryRoom } from "../components/structures/SpaceRoomDirectory";
 import RoomViewStore from "./RoomViewStore";
 import { Action } from "../dispatcher/actions";
 import { arrayHasDiff } from "../utils/arrays";
@@ -184,10 +184,7 @@ export class SpaceStoreClass extends AsyncStoreWithClient<IState> {
 
     public fetchSuggestedRooms = async (space: Room, limit = MAX_SUGGESTED_ROOMS): Promise<ISuggestedRoom[]> => {
         try {
-            const data: {
-                rooms: ISpaceSummaryRoom[];
-                events: ISpaceSummaryEvent[];
-            } = await this.matrixClient.getSpaceSummary(space.roomId, 0, true, false, limit);
+            const data = await this.matrixClient.getSpaceSummary(space.roomId, 0, true, false, limit);
 
             const viaMap = new EnhancedMap<string, Set<string>>();
             data.events.forEach(ev => {
diff --git a/src/utils/Timer.ts b/src/utils/Timer.ts
index 2317ed934b..38703c1299 100644
--- a/src/utils/Timer.ts
+++ b/src/utils/Timer.ts
@@ -26,7 +26,7 @@ Once a timer is finished or aborted, it can't be started again
 a new one through `clone()` or `cloneIfRun()`.
 */
 export default class Timer {
-    private timerHandle: NodeJS.Timeout;
+    private timerHandle: number;
     private startTs: number;
     private promise: Promise<void>;
     private resolve: () => void;
diff --git a/src/utils/WidgetUtils.ts b/src/utils/WidgetUtils.ts
index 222837511d..e27381b1cf 100644
--- a/src/utils/WidgetUtils.ts
+++ b/src/utils/WidgetUtils.ts
@@ -386,7 +386,7 @@ export default class WidgetUtils {
         });
     }
 
-    static removeIntegrationManagerWidgets(): Promise<void> {
+    static async removeIntegrationManagerWidgets(): Promise<void> {
         const client = MatrixClientPeg.get();
         if (!client) {
             throw new Error('User not logged in');
@@ -399,7 +399,7 @@ export default class WidgetUtils {
                 delete userWidgets[key];
             }
         });
-        return client.setAccountData('m.widgets', userWidgets);
+        await client.setAccountData('m.widgets', userWidgets);
     }
 
     static addIntegrationManagerWidget(name: string, uiUrl: string, apiUrl: string): Promise<void> {
@@ -416,7 +416,7 @@ export default class WidgetUtils {
      * Remove all stickerpicker widgets (stickerpickers are user widgets by nature)
      * @return {Promise} Resolves on account data updated
      */
-    static removeStickerpickerWidgets(): Promise<void> {
+    static async removeStickerpickerWidgets(): Promise<void> {
         const client = MatrixClientPeg.get();
         if (!client) {
             throw new Error('User not logged in');
@@ -429,7 +429,7 @@ export default class WidgetUtils {
                 delete userWidgets[key];
             }
         });
-        return client.setAccountData('m.widgets', userWidgets);
+        await client.setAccountData('m.widgets', userWidgets);
     }
 
     static makeAppConfig(
diff --git a/src/verification.ts b/src/verification.ts
index 719c0ec5b3..98844302df 100644
--- a/src/verification.ts
+++ b/src/verification.ts
@@ -22,7 +22,7 @@ import Modal from './Modal';
 import { RightPanelPhases } from "./stores/RightPanelStorePhases";
 import { findDMForUser } from './createRoom';
 import { accessSecretStorage } from './SecurityManager';
-import { verificationMethods } from 'matrix-js-sdk/src/crypto';
+import { verificationMethods as VerificationMethods } from 'matrix-js-sdk/src/crypto';
 import { Action } from './dispatcher/actions';
 import UntrustedDeviceDialog from "./components/views/dialogs/UntrustedDeviceDialog";
 import { IDevice } from "./components/views/right_panel/UserInfo";
@@ -63,7 +63,7 @@ export async function verifyDevice(user: User, device: IDevice) {
                 const verificationRequestPromise = cli.legacyDeviceVerification(
                     user.userId,
                     device.deviceId,
-                    verificationMethods.SAS,
+                    VerificationMethods.SAS,
                 );
                 dis.dispatch({
                     action: Action.SetRightPanelPhase,