diff --git a/client/src/Player.ts b/client/src/Player.ts
index 424ff8a..77aaffa 100644
--- a/client/src/Player.ts
+++ b/client/src/Player.ts
@@ -3,7 +3,6 @@ import {InterjectionPlayer} from "./interjection/Player";
 import {BufferControl} from "./live/BufferCtrl";
 import {MseWrapper} from "./live/MseWrapper";
 import {API} from "live-video-streamer-common";
-import {assertType} from "@ckitching/typescript-is";
 import {EventDispatcher} from "./EventDispatcher";
 
 /**
@@ -324,7 +323,6 @@ export class Player extends EventDispatcher<keyof PlayerEventMap, PlayerEventMap
             switch (controlChunkType) {
                 case API.ControlChunkType.jsonObject:
                     const j = JSON.parse(new TextDecoder().decode(data));
-                    assertType<API.JsonObjectControlChunk>(j);
                     this.onJsonObject(j);
                     break;
                 case API.ControlChunkType.userJsonObject:
@@ -356,8 +354,7 @@ export class Player extends EventDispatcher<keyof PlayerEventMap, PlayerEventMap
         // Fetch the channel index
         const channelIndexResponse: Response = await fetch(this.server + channelIndexPath);
         if (channelIndexResponse.status === 200) {
-            const channelIndex: unknown = await channelIndexResponse.json();
-            assertType<API.ChannelIndex>(channelIndex);
+            const channelIndex = await channelIndexResponse.json() as API.ChannelIndex;
 
             if (!first && JSON.stringify(this.channelIndex) !== JSON.stringify(this.channelIndex)) {
                 // The channel index has changed.
diff --git a/client/src/interjection/Player.ts b/client/src/interjection/Player.ts
index 7973ada..9d54f15 100644
--- a/client/src/interjection/Player.ts
+++ b/client/src/interjection/Player.ts
@@ -2,7 +2,6 @@ import {MseWrapper} from "./MseWrapper";
 import {Interjection, InterjectionSelection} from "./Selection";
 import {waitForPts} from "../Util"
 import {API, sleep} from "live-video-streamer-common";
-import {assertType} from "@ckitching/typescript-is";
 import {EventDispatcher} from "../EventDispatcher";
 import {PlayerErrorEvent} from "../Player";
 
@@ -102,7 +101,6 @@ export class InterjectionPlayer extends EventDispatcher<keyof InterjectionPlayer
         this.spawn(async (): Promise<void> => {
             // Download the interjection set metadata.
             const j = await this.download(`${this.request.setUrl}/interjection-set.json`, "json", "set metadata");
-            assertType<API.InterjectionSet>(j);
             this.interjectionSet = j;
 
             // Select and show the first selection of interjections.
@@ -286,7 +284,6 @@ export class InterjectionPlayer extends EventDispatcher<keyof InterjectionPlayer
         /* Download the interjection metadata. */
         const interjectionMetadata = await this.download(`${this.request.setUrl}/${name}/interjection.json`, "json",
                                                          "metadata");
-        assertType<API.Interjection>(interjectionMetadata);
 
         /* Enqueue the downloading of the interjection's streams. */
         const numSegments = Math.ceil(interjectionMetadata.contentDuration / interjectionMetadata.segmentDuration);
diff --git a/client/src/live/MseWrapper.ts b/client/src/live/MseWrapper.ts
index 377a8c5..9163b25 100644
--- a/client/src/live/MseWrapper.ts
+++ b/client/src/live/MseWrapper.ts
@@ -1,6 +1,5 @@
 import {TimestampInfo} from "./Deinterleave";
 import {API, waitForEvent} from "live-video-streamer-common";
-import {assertType} from "@ckitching/typescript-is";
 import {SegmentDownloader, ReceivedInfo} from "./SegmentDownloader";
 import {getMediaSource} from "../MediaSource";
 import {getFullMimeType, Stream, StreamStartEvent} from "../Stream";
@@ -174,17 +173,11 @@ export class MseWrapper extends EventDispatcher<keyof MseEventMap, MseEventMap>
         }
     }
 
-    private async setupStreams(manifest: string, videoInfo: any, videoInit: ArrayBuffer, audioInfo: any = null,
+    private async setupStreams(manifest: string, videoInfo: API.SegmentIndexDescriptor, videoInit: ArrayBuffer, audioInfo: any = null,
                                audioInit: ArrayBuffer | null = null): Promise<void> {
         /* Clean up whatever already existed. */
         this.cleanup();
 
-        /* Validate. */
-        assertType<API.SegmentIndexDescriptor>(videoInfo);
-        if (audioInfo !== null) {
-            assertType<API.SegmentIndexDescriptor>(audioInfo);
-        }
-
         /* Create afresh. */
         this.videoMediaSource = getMediaSource();
         this.video.src = URL.createObjectURL(this.videoMediaSource);
diff --git a/client/src/live/SegmentDownloader.ts b/client/src/live/SegmentDownloader.ts
index 258bd63..0553d42 100644
--- a/client/src/live/SegmentDownloader.ts
+++ b/client/src/live/SegmentDownloader.ts
@@ -1,7 +1,6 @@
 import {API, assertNonNull} from "live-video-streamer-common";
 import {Deinterleaver} from "./Deinterleave";
 import {Stream} from "../Stream";
-import {assertType} from "@ckitching/typescript-is";
 import {MseControlChunkEvent, MseEventMap, MseReceivedEvent, MseTimestampEvent} from "./MseWrapper";
 import {EventDispatcher} from "../EventDispatcher";
 import {PlayerErrorEvent} from "../Player";
@@ -71,8 +70,7 @@ export class SegmentDownloader extends EventDispatcher<keyof MseEventMap, MseEve
                 if (response.status !== 200) {
                     throw new Error(`Fetching stream index descriptor gave HTTP status code ${response.status}`);
                 }
-                const newInfo: unknown = await response.json();
-                assertType<API.SegmentIndexDescriptor>(newInfo);
+                const newInfo = await response.json();
                 this.setSegmentDownloadSchedule(newInfo);
             } catch (ex: any) {
                 const e = ex as Error;