diff --git a/src/CallHandler.tsx b/src/CallHandler.tsx
index 8b1dc41b07..6b66a614d2 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, CallEvent, CallParty } from "matrix-js-sdk/lib/webrtc/call";
+import { MatrixCall, CallErrorCode, CallState, CallEvent, CallParty } from "matrix-js-sdk/lib/webrtc/call";
 
 enum AudioID {
     Ring = 'ringAudio',
@@ -86,6 +86,16 @@ enum AudioID {
     Busy = 'busyAudio',
 }
 
+// Unlike 'CallType' in js-sdk, this one includes screen sharing
+// (because a screen sharing call is only a screen sharing call to the caller,
+// to the callee it's just a video call, at least as far as the current impl
+// is concerned).
+export enum PlaceCallType {
+    Voice = 'voice',
+    Video = 'video',
+    ScreenSharing = 'screensharing',
+}
+
 export default class CallHandler {
     private calls = new Map<string, MatrixCall>();
     private audioPromises = new Map<AudioID, Promise<void>>();
@@ -271,18 +281,21 @@ export default class CallHandler {
     }
 
 
-    private placeCall(roomId: string, type: CallType, localElement: HTMLVideoElement, remoteElement: HTMLVideoElement) {
+    private placeCall(
+        roomId: string, type: PlaceCallType,
+        localElement: HTMLVideoElement, remoteElement: HTMLVideoElement,
+    ) {
         const call = Matrix.createNewMatrixCall(MatrixClientPeg.get(), roomId);
         this.calls.set(roomId, call);
         this.setCallListeners(call);
-        if (type === 'voice') {
+        if (type === PlaceCallType.Voice) {
             call.placeVoiceCall();
         } else if (type === 'video') {
             call.placeVideoCall(
                 remoteElement,
                 localElement,
             );
-        } else if (type === 'screensharing') {
+        } else if (type === PlaceCallType.ScreenSharing) {
             const screenCapErrorString = PlatformPeg.get().screenCaptureErrorString();
             if (screenCapErrorString) {
                 this.removeCallForRoom(roomId);
diff --git a/src/components/views/rooms/MessageComposer.js b/src/components/views/rooms/MessageComposer.js
index 2ca1cc5aef..1708e2e7f1 100644
--- a/src/components/views/rooms/MessageComposer.js
+++ b/src/components/views/rooms/MessageComposer.js
@@ -37,6 +37,7 @@ import WidgetStore from "../../../stores/WidgetStore";
 import WidgetUtils from "../../../utils/WidgetUtils";
 import {UPDATE_EVENT} from "../../../stores/AsyncStore";
 import ActiveWidgetStore from "../../../stores/ActiveWidgetStore";
+import { PlaceCallType } from "../../../CallHandler";
 
 function ComposerAvatar(props) {
     const MemberStatusMessageAvatar = sdk.getComponent('avatars.MemberStatusMessageAvatar');
@@ -53,7 +54,7 @@ function CallButton(props) {
     const onVoiceCallClick = (ev) => {
         dis.dispatch({
             action: 'place_call',
-            type: "voice",
+            type: PlaceCallType.Voice,
             room_id: props.roomId,
         });
     };
@@ -73,7 +74,7 @@ function VideoCallButton(props) {
     const onCallClick = (ev) => {
         dis.dispatch({
             action: 'place_call',
-            type: ev.shiftKey ? "screensharing" : "video",
+            type: ev.shiftKey ? PlaceCallType.ScreenSharing : PlaceCallType.Video,
             room_id: props.roomId,
         });
     };