diff --git a/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts b/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
index 04554955cd18..7f5bf1a87d85 100644
--- a/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
+++ b/packages/angular/build/src/builders/unit-test/runners/vitest/plugins.ts
@@ -117,8 +117,9 @@ export async function createVitestConfigPlugin(
         test: {
           setupFiles,
           globals: true,
-          // Default to `false` to align with the Karma/Jasmine experience.
-          isolate: false,
+          // Default to `false` to align with the Karma/Jasmine experience when using DOM emulation
+          // TODO: Investigate how this can be the default for browser mode as well
+          isolate: !!browser?.enabled,
           sequence: { setupFiles: 'list' },
         },
         optimizeDeps: {