diff --git a/packages/schematics/angular/web-worker/index.ts b/packages/schematics/angular/web-worker/index.ts
index a19e2b714174..45e1f39ad34c 100644
--- a/packages/schematics/angular/web-worker/index.ts
+++ b/packages/schematics/angular/web-worker/index.ts
@@ -26,6 +26,7 @@ import { parseName } from '../utility/parse-name';
 import { relativePathToWorkspaceRoot } from '../utility/paths';
 import { createProjectSchematic } from '../utility/project';
 import { buildDefaultPath, updateWorkspace } from '../utility/workspace';
+import { Builders } from '../utility/workspace-models';
 import { Schema as WebWorkerOptions } from './schema';
 
 function addSnippet(options: WebWorkerOptions): Rule {
@@ -115,7 +116,8 @@ const webWorkerSchematic: RuleFactory<WebWorkerOptions> = createProjectSchematic
 
         const workerConfigPath = join(root, 'tsconfig.worker.json');
         (buildTarget.options ??= {}).webWorkerTsConfig ??= workerConfigPath;
-        if (testTarget) {
+        // The unit-test builder has no `webWorkerTsConfig` option and reads it from the build target.
+        if (testTarget && testTarget.builder !== Builders.BuildUnitTest) {
           (testTarget.options ??= {}).webWorkerTsConfig ??= workerConfigPath;
         }
       }),
diff --git a/packages/schematics/angular/web-worker/index_spec.ts b/packages/schematics/angular/web-worker/index_spec.ts
index c1ab48b8d196..a922a6d3cee6 100644
--- a/packages/schematics/angular/web-worker/index_spec.ts
+++ b/packages/schematics/angular/web-worker/index_spec.ts
@@ -9,6 +9,7 @@
 import { SchematicTestRunner, UnitTestTree } from '@angular-devkit/schematics/testing';
 import { parse as parseJson } from 'jsonc-parser';
 import { Schema as ApplicationOptions } from '../application/schema';
+import { Builders } from '../utility/workspace-models';
 import { Schema as WorkspaceOptions } from '../workspace/schema';
 import { Schema as WebWorkerOptions } from './schema';
 
@@ -68,6 +69,25 @@ describe('Web Worker Schematic', () => {
     );
   });
 
+  it('should not add the webWorkerTsConfig option to a unit-test builder test target', async () => {
+    const tree = await schematicRunner.runSchematic('web-worker', defaultOptions, appTree);
+    const { projects } = JSON.parse(tree.readContent('/angular.json'));
+    expect(projects.bar.architect.test.builder).toBe(Builders.BuildUnitTest);
+    expect(projects.bar.architect.test.options?.webWorkerTsConfig).toBeUndefined();
+  });
+
+  it('should add the webWorkerTsConfig option to a karma builder test target', async () => {
+    const config = JSON.parse(appTree.readContent('/angular.json'));
+    config.projects.bar.architect.test = { builder: Builders.BuildKarma, options: {} };
+    appTree.overwrite('/angular.json', JSON.stringify(config, undefined, 2));
+
+    const tree = await schematicRunner.runSchematic('web-worker', defaultOptions, appTree);
+    const { projects } = JSON.parse(tree.readContent('/angular.json'));
+    expect(projects.bar.architect.test.options.webWorkerTsConfig).toBe(
+      'projects/bar/tsconfig.worker.json',
+    );
+  });
+
   it('should add snippet to sibling file', async () => {
     const tree = await schematicRunner.runSchematic('web-worker', defaultOptions, appTree);
     const appComponent = tree.readContent('/projects/bar/src/app/app.ts');