diff --git a/src/Terms.ts b/src/Terms.ts
index 3859cc1c73..e96081b7b7 100644
--- a/src/Terms.ts
+++ b/src/Terms.ts
@@ -15,6 +15,7 @@ limitations under the License.
 */
 
 import classNames from 'classnames';
+import { SERVICE_TYPES } from '../../matrix-js-sdk/src/service-types';
 
 import { MatrixClientPeg } from './MatrixClientPeg';
 import * as sdk from '.';
@@ -32,7 +33,7 @@ export class Service {
      * @param {string} baseUrl The Base URL of the service (ie. before '/_matrix')
      * @param {string} accessToken The user's access token for the service
      */
-    constructor(public serviceType: string, public baseUrl: string, public accessToken: string) {
+    constructor(public serviceType: SERVICE_TYPES, public baseUrl: string, public accessToken: string) {
     }
 }
 
diff --git a/src/components/structures/FilePanel.tsx b/src/components/structures/FilePanel.tsx
index 14380341d1..d47ea11a3c 100644
--- a/src/components/structures/FilePanel.tsx
+++ b/src/components/structures/FilePanel.tsx
@@ -19,6 +19,7 @@ import React from 'react';
 
 import { Filter } from 'matrix-js-sdk/src/filter';
 import { EventTimelineSet } from "matrix-js-sdk/src/models/event-timeline-set";
+import { Direction } from "matrix-js-sdk/src/models/event-timeline";
 import { MatrixEvent } from "matrix-js-sdk/src/models/event";
 import { Room } from 'matrix-js-sdk/src/models/room';
 import { TimelineWindow } from 'matrix-js-sdk/src/timeline-window';
@@ -153,7 +154,11 @@ class FilePanel extends React.Component<IProps, IState> {
         return timelineSet;
     }
 
-    private onPaginationRequest = (timelineWindow: TimelineWindow, direction: string, limit: number): void => {
+    private onPaginationRequest = (
+        timelineWindow: TimelineWindow,
+        direction: Direction,
+        limit: number,
+    ): Promise<boolean> => {
         const client = MatrixClientPeg.get();
         const eventIndex = EventIndexPeg.get();
         const roomId = this.props.roomId;
diff --git a/src/components/structures/TimelinePanel.tsx b/src/components/structures/TimelinePanel.tsx
index d7d3b33b3e..9253fb786b 100644
--- a/src/components/structures/TimelinePanel.tsx
+++ b/src/components/structures/TimelinePanel.tsx
@@ -19,7 +19,7 @@ import ReactDOM from "react-dom";
 import { NotificationCountType, Room } from "matrix-js-sdk/src/models/room";
 import { MatrixEvent } from "matrix-js-sdk/src/models/event";
 import { EventTimelineSet } from "matrix-js-sdk/src/models/event-timeline-set";
-import { EventTimeline } from "matrix-js-sdk/src/models/event-timeline";
+import { Direction, EventTimeline } from "matrix-js-sdk/src/models/event-timeline";
 import { TimelineWindow } from "matrix-js-sdk/src/timeline-window";
 import { EventType, RelationType } from 'matrix-js-sdk/src/@types/event';
 import { SyncState } from 'matrix-js-sdk/src/sync.api';
@@ -388,7 +388,7 @@ class TimelinePanel extends React.Component<IProps, IState> {
 
     private onPaginationRequest = (
         timelineWindow: TimelineWindow,
-        direction: string,
+        direction: Direction,
         size: number,
     ): Promise<boolean> => {
         if (this.props.onPaginationRequest) {
diff --git a/src/indexing/EventIndex.ts b/src/indexing/EventIndex.ts
index 103a2f0809..c84d446197 100644
--- a/src/indexing/EventIndex.ts
+++ b/src/indexing/EventIndex.ts
@@ -862,7 +862,7 @@ export default class EventIndex extends EventEmitter {
      * @returns {Promise<boolean>} Resolves to a boolean which is true if more
      * events were successfully retrieved.
      */
-    public paginateTimelineWindow(room: Room, timelineWindow: TimelineWindow, direction: string, limit: number) {
+    public paginateTimelineWindow(room: Room, timelineWindow: TimelineWindow, direction: Direction, limit: number) {
         const tl = timelineWindow.getTimelineIndex(direction);
 
         if (!tl) return Promise.resolve(false);