diff --git a/src/client.ts b/src/client.ts
index 0fab62a30ae..3ce67168ce9 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -1322,7 +1322,7 @@ export class MatrixClient extends EventEmitter {
     public async createGroupCall(
         roomId: string,
         type: GroupCallType,
-        isPtt, boolean,
+        isPtt: boolean,
         intent: GroupCallIntent,
         dataChannelsEnabled?: boolean,
         dataChannelOptions?: IGroupCallDataChannelOptions,