diff --git a/goldens/public-api/angular_devkit/schematics/index.md b/goldens/public-api/angular_devkit/schematics/index.md
index 2d9f6a616bb1..67d13a878814 100644
--- a/goldens/public-api/angular_devkit/schematics/index.md
+++ b/goldens/public-api/angular_devkit/schematics/index.md
@@ -495,13 +495,13 @@ export class HostSink extends SimpleSinkBase {
     // (undocumented)
     _done(): Observable<void>;
     // (undocumented)
-    protected _filesToCreate: Map<Path, UpdateBufferBase>;
+    protected _filesToCreate: Map<Path, Buffer>;
     // (undocumented)
     protected _filesToDelete: Set<Path>;
     // (undocumented)
     protected _filesToRename: Set<[Path, Path]>;
     // (undocumented)
-    protected _filesToUpdate: Map<Path, UpdateBufferBase>;
+    protected _filesToUpdate: Map<Path, Buffer>;
     // (undocumented)
     protected _force: boolean;
     // (undocumented)
diff --git a/packages/angular/pwa/pwa/index.ts b/packages/angular/pwa/pwa/index.ts
index 03627ca5a615..2b4996f0f324 100644
--- a/packages/angular/pwa/pwa/index.ts
+++ b/packages/angular/pwa/pwa/index.ts
@@ -167,12 +167,7 @@ export default function (options: PwaOptions): Rule {
     return chain([
       externalSchematic('@schematics/angular', 'service-worker', swOptions),
       mergeWith(apply(url('./files/root'), [template({ ...options }), move(sourcePath)])),
-      mergeWith(
-        apply(url('./files/assets'), [
-          template({ ...options }),
-          move(posix.join(sourcePath, 'assets')),
-        ]),
-      ),
+      mergeWith(apply(url('./files/assets'), [move(posix.join(sourcePath, 'assets'))])),
       ...[...indexFiles].map((path) => updateIndexFile(path)),
     ]);
   };
diff --git a/packages/angular_devkit/schematics/src/sink/dryrun.ts b/packages/angular_devkit/schematics/src/sink/dryrun.ts
index 33799f2ddf2c..db4b296b81d6 100644
--- a/packages/angular_devkit/schematics/src/sink/dryrun.ts
+++ b/packages/angular_devkit/schematics/src/sink/dryrun.ts
@@ -117,10 +117,10 @@ export class DryRunSink extends HostSink {
         return;
       }
 
-      this._subject.next({ kind: 'create', path, content: content.generate() });
+      this._subject.next({ kind: 'create', path, content });
     });
     this._filesToUpdate.forEach((content, path) => {
-      this._subject.next({ kind: 'update', path, content: content.generate() });
+      this._subject.next({ kind: 'update', path, content });
     });
 
     this._subject.complete();
diff --git a/packages/angular_devkit/schematics/src/sink/host.ts b/packages/angular_devkit/schematics/src/sink/host.ts
index a83fc568503e..10da1a67a8d1 100644
--- a/packages/angular_devkit/schematics/src/sink/host.ts
+++ b/packages/angular_devkit/schematics/src/sink/host.ts
@@ -17,14 +17,13 @@ import {
   reduce,
 } from 'rxjs';
 import { CreateFileAction } from '../tree/action';
-import { UpdateBufferBase } from '../utility/update-buffer';
 import { SimpleSinkBase } from './sink';
 
 export class HostSink extends SimpleSinkBase {
   protected _filesToDelete = new Set<Path>();
   protected _filesToRename = new Set<[Path, Path]>();
-  protected _filesToCreate = new Map<Path, UpdateBufferBase>();
-  protected _filesToUpdate = new Map<Path, UpdateBufferBase>();
+  protected _filesToCreate = new Map<Path, Buffer>();
+  protected _filesToUpdate = new Map<Path, Buffer>();
 
   constructor(protected _host: virtualFs.Host, protected _force = false) {
     super();
@@ -56,20 +55,23 @@ export class HostSink extends SimpleSinkBase {
   }
 
   protected _overwriteFile(path: Path, content: Buffer): Observable<void> {
-    this._filesToUpdate.set(path, UpdateBufferBase.create(content));
+    this._filesToUpdate.set(path, content);
 
     return EMPTY;
   }
+
   protected _createFile(path: Path, content: Buffer): Observable<void> {
-    this._filesToCreate.set(path, UpdateBufferBase.create(content));
+    this._filesToCreate.set(path, content);
 
     return EMPTY;
   }
+
   protected _renameFile(from: Path, to: Path): Observable<void> {
     this._filesToRename.add([from, to]);
 
     return EMPTY;
   }
+
   protected _deleteFile(path: Path): Observable<void> {
     if (this._filesToCreate.has(path)) {
       this._filesToCreate.delete(path);
@@ -91,14 +93,10 @@ export class HostSink extends SimpleSinkBase {
         concatMap(([_, [path, to]]) => this._host.rename(path, to)),
       ),
       observableFrom([...this._filesToCreate.entries()]).pipe(
-        concatMap(([path, buffer]) => {
-          return this._host.write(path, buffer.generate() as {} as virtualFs.FileBuffer);
-        }),
+        concatMap(([path, buffer]) => this._host.write(path, buffer)),
       ),
       observableFrom([...this._filesToUpdate.entries()]).pipe(
-        concatMap(([path, buffer]) => {
-          return this._host.write(path, buffer.generate() as {} as virtualFs.FileBuffer);
-        }),
+        concatMap(([path, buffer]) => this._host.write(path, buffer)),
       ),
     ).pipe(reduce(() => {}));
   }
diff --git a/packages/angular_devkit/schematics/src/tree/recorder.ts b/packages/angular_devkit/schematics/src/tree/recorder.ts
index 236996306dce..13551fea0c0c 100644
--- a/packages/angular_devkit/schematics/src/tree/recorder.ts
+++ b/packages/angular_devkit/schematics/src/tree/recorder.ts
@@ -17,7 +17,7 @@ export class UpdateRecorderBase implements UpdateRecorder {
 
   constructor(entry: FileEntry) {
     this._original = Buffer.from(entry.content);
-    this._content = UpdateBufferBase.create(entry.content);
+    this._content = UpdateBufferBase.create(entry.path, entry.content);
     this._path = entry.path;
   }
 
diff --git a/packages/angular_devkit/schematics/src/utility/update-buffer.ts b/packages/angular_devkit/schematics/src/utility/update-buffer.ts
index d520e4dd4805..eac10b8d4079 100644
--- a/packages/angular_devkit/schematics/src/utility/update-buffer.ts
+++ b/packages/angular_devkit/schematics/src/utility/update-buffer.ts
@@ -8,6 +8,7 @@
 
 import { BaseException } from '@angular-devkit/core';
 import MagicString from 'magic-string';
+import { TextDecoder } from 'node:util';
 
 export class IndexOutOfBoundException extends BaseException {
   constructor(index: number, min: number, max = Infinity) {
@@ -32,11 +33,23 @@ export abstract class UpdateBufferBase {
   /**
    * Creates an UpdateBufferBase instance.
    *
+   * @param contentPath The path of the update buffer instance.
    * @param originalContent The original content of the update buffer instance.
    * @returns An UpdateBufferBase instance.
    */
-  static create(originalContent: Buffer): UpdateBufferBase {
-    return new UpdateBuffer(originalContent);
+  static create(contentPath: string, originalContent: Buffer): UpdateBufferBase {
+    try {
+      // We only support utf8 encoding.
+      new TextDecoder('utf8', { fatal: true }).decode(originalContent);
+
+      return new UpdateBuffer(originalContent);
+    } catch (e) {
+      if (e instanceof TypeError) {
+        throw new Error(`Failed to decode "${contentPath}" as UTF-8 text.`);
+      }
+
+      throw e;
+    }
   }
 }