diff --git a/packages/localize/schematics/ng-add/index.ts b/packages/localize/schematics/ng-add/index.ts
index b5fa0fafa4a4..409cf5e94283 100644
--- a/packages/localize/schematics/ng-add/index.ts
+++ b/packages/localize/schematics/ng-add/index.ts
@@ -36,6 +36,7 @@ function addPolyfillToConfig(projectName: string): Rule {
     for (const target of project.targets.values()) {
       switch (target.builder) {
         case AngularBuilder.Karma:
+        case AngularBuilder.BuildKarma:
         case AngularBuilder.Server:
         case AngularBuilder.Browser:
         case AngularBuilder.BrowserEsbuild:
diff --git a/packages/localize/schematics/ng-add/index_spec.ts b/packages/localize/schematics/ng-add/index_spec.ts
index b6f37abbd695..c9a4f9666eaa 100644
--- a/packages/localize/schematics/ng-add/index_spec.ts
+++ b/packages/localize/schematics/ng-add/index_spec.ts
@@ -77,6 +77,13 @@ describe('ng-add schematic', () => {
                   polyfills: 'zone.js',
                 },
               },
+              testKarmaBuild: {
+                builder: '@angular/build:karma',
+                options: {
+                  tsConfig: './tsconfig.spec.json',
+                  polyfills: 'zone.js',
+                },
+              },
               server: {
                 builder: '@angular-devkit/build-angular:server',
                 options: {
@@ -173,6 +180,13 @@ describe('ng-add schematic', () => {
     expect(polyfills).toEqual(['zone.js', '@angular/localize/init']);
   });
 
+  it(`should add '@angular/localize/init' in 'polyfills' in karma application builder`, async () => {
+    host = await schematicRunner.runSchematic('ng-add', defaultOptions, host);
+    const workspace = host.readJson('angular.json') as any;
+    const polyfills = workspace.projects['demo'].architect.testKarmaBuild.options.polyfills;
+    expect(polyfills).toEqual(['zone.js', '@angular/localize/init']);
+  });
+
   it(`should add '@angular/localize/init' in 'polyfills' in browser builder`, async () => {
     host = await schematicRunner.runSchematic('ng-add', defaultOptions, host);
     const workspace = host.readJson('angular.json') as any;