diff --git a/src/CallHandler.tsx b/src/CallHandler.tsx
index 22939b2cc8..8b1dc41b07 100644
--- a/src/CallHandler.tsx
+++ b/src/CallHandler.tsx
@@ -77,7 +77,7 @@ import ErrorDialog from "./components/views/dialogs/ErrorDialog";
 import WidgetStore from "./stores/WidgetStore";
 import { WidgetMessagingStore } from "./stores/widgets/WidgetMessagingStore";
 import { ElementWidgetActions } from "./stores/widgets/ElementWidgetActions";
-import { MatrixCall, CallErrorCode, CallState, CallType } from "matrix-js-sdk/lib/webrtc/call";
+import { MatrixCall, CallErrorCode, CallState, CallType, CallEvent, CallParty } from "matrix-js-sdk/lib/webrtc/call";
 
 enum AudioID {
     Ring = 'ringAudio',
@@ -119,7 +119,7 @@ export default class CallHandler {
 
     getAnyActiveCall() {
         for (const call of this.calls.values()) {
-            if (call.state !== "ended") {
+            if (call.state !== CallState.Ended) {
                 return call;
             }
         }
@@ -170,7 +170,7 @@ export default class CallHandler {
     }
 
     private setCallListeners(call: MatrixCall) {
-        call.on("error", (err) => {
+        call.on(CallEvent.Error, (err) => {
             console.error("Call error:", err);
             if (
                 MatrixClientPeg.get().getTurnServers().length === 0 &&
@@ -185,10 +185,10 @@ export default class CallHandler {
                 description: err.message,
             });
         });
-        call.on("hangup", () => {
+        call.on(CallEvent.Hangup, () => {
             this.removeCallForRoom(call.roomId);
         });
-        call.on("state", (newState: CallState, oldState: CallState) => {
+        call.on(CallEvent.State, (newState: CallState, oldState: CallState) => {
             this.setCallState(call, newState);
 
             switch (oldState) {
@@ -210,8 +210,8 @@ export default class CallHandler {
                 case CallState.Ended:
                     this.removeCallForRoom(call.roomId);
                     if (oldState === CallState.InviteSent && (
-                        call.hangupParty === "remote" ||
-                        (call.hangupParty === "local" && call.hangupReason === "invite_timeout")
+                        call.hangupParty === CallParty.Remote ||
+                        (call.hangupParty === CallParty.Local && call.hangupReason === CallErrorCode.InviteTimeout)
                     )) {
                         this.play(AudioID.Busy);
                         Modal.createTrackedDialog('Call Handler', 'Call Timeout', ErrorDialog, {
diff --git a/src/components/structures/RoomStatusBar.js b/src/components/structures/RoomStatusBar.js
index 453663a261..3e07d617de 100644
--- a/src/components/structures/RoomStatusBar.js
+++ b/src/components/structures/RoomStatusBar.js
@@ -24,6 +24,7 @@ import Resend from '../../Resend';
 import dis from '../../dispatcher/dispatcher';
 import {messageForResourceLimitError, messageForSendError} from '../../utils/ErrorUtils';
 import {Action} from "../../dispatcher/actions";
+import { CallState, CallType } from 'matrix-js-sdk/lib/webrtc/call';
 
 const STATUS_BAR_HIDDEN = 0;
 const STATUS_BAR_EXPANDED = 1;
@@ -122,7 +123,7 @@ export default class RoomStatusBar extends React.Component {
     };
 
     _showCallBar() {
-        return this.props.callState !== 'ended' && this.props.callState !== 'ringing';
+        return this.props.callState !== CallState.Ended && this.props.callState !== CallState.Ringing;
     }
 
     _onResendAllClick = () => {
@@ -275,16 +276,16 @@ export default class RoomStatusBar extends React.Component {
 
     _getCallStatusText() {
         switch (this.props.callState) {
-            case 'create_offer':
-            case 'invite_sent':
+            case CallState.CreateOffer:
+            case CallState.InviteSent:
                 return _t('Calling...');
-            case 'connecting':
-            case 'create_answer':
+            case CallState.Connecting:
+            case CallState.CreateAnswer:
                 return _t('Call connecting...');
-            case 'connected':
+            case CallState.Connected:
                 return _t('Active call');
-            case 'wait_local_media':
-                if (this.props.callType === 'video') {
+            case CallState.WaitLocalMedia:
+                if (this.props.callType === CallType.Video) {
                     return _t('Starting camera...');
                 } else {
                     return _t('Starting microphone...');
diff --git a/src/components/structures/RoomView.tsx b/src/components/structures/RoomView.tsx
index 2a6d0b5de8..8b90b6b810 100644
--- a/src/components/structures/RoomView.tsx
+++ b/src/components/structures/RoomView.tsx
@@ -71,7 +71,7 @@ import RoomHeader from "../views/rooms/RoomHeader";
 import TintableSvg from "../views/elements/TintableSvg";
 import {XOR} from "../../@types/common";
 import { IThreepidInvite } from "../../stores/ThreepidInviteStore";
-import { CallState, MatrixCall } from "matrix-js-sdk/lib/webrtc/call";
+import { CallState, CallType, MatrixCall } from "matrix-js-sdk/lib/webrtc/call";
 
 const DEBUG = false;
 let debuglog = function(msg: string) {};
@@ -1892,7 +1892,7 @@ export default class RoomView extends React.Component<IProps, IState> {
         if (activeCall) {
             let zoomButton; let videoMuteButton;
 
-            if (activeCall.type === "video") {
+            if (activeCall.type === CallType.Video) {
                 zoomButton = (
                     <div className="mx_RoomView_voipButton" onClick={this.onFullscreenClick} title={_t("Fill screen")}>
                         <TintableSvg