diff --git a/packages/test-utils/src/testUtils/apis/ErrorApi/MockErrorApi.ts b/packages/test-utils/src/testUtils/apis/ErrorApi/MockErrorApi.ts
index 9b22a352e8..7bf50314d0 100644
--- a/packages/test-utils/src/testUtils/apis/ErrorApi/MockErrorApi.ts
+++ b/packages/test-utils/src/testUtils/apis/ErrorApi/MockErrorApi.ts
@@ -14,12 +14,7 @@
  * limitations under the License.
  */
 
-import {
-  ErrorApi,
-  ErrorContext,
-  errorApiRef,
-  Observable,
-} from '@backstage/core-api';
+import { ErrorApi, ErrorContext, Observable } from '@backstage/core-api';
 
 type Options = {
   collect?: boolean;
@@ -40,12 +35,6 @@ const nullObservable = {
 };
 
 export class MockErrorApi implements ErrorApi {
-  static factory = {
-    implements: errorApiRef,
-    deps: {},
-    factory: () => new MockErrorApi(),
-  };
-
   private readonly errors = new Array<ErrorWithContext>();
   private readonly waiters = new Set<Waiter>();
 
diff --git a/packages/test-utils/src/testUtils/apis/StorageApi/MockStorageApi.ts b/packages/test-utils/src/testUtils/apis/StorageApi/MockStorageApi.ts
index a3a4ef16d6..006b44a49c 100644
--- a/packages/test-utils/src/testUtils/apis/StorageApi/MockStorageApi.ts
+++ b/packages/test-utils/src/testUtils/apis/StorageApi/MockStorageApi.ts
@@ -17,7 +17,6 @@
 import {
   Observable,
   StorageApi,
-  storageApiRef,
   StorageValueChange,
 } from '@backstage/core-api';
 import ObservableImpl from 'zen-observable';
@@ -25,12 +24,6 @@ import ObservableImpl from 'zen-observable';
 export type MockStorageBucket = { [key: string]: any };
 
 export class MockStorageApi implements StorageApi {
-  static factory = {
-    implements: storageApiRef,
-    deps: {},
-    factory: () => MockStorageApi.create(),
-  };
-
   private readonly namespace: string;
   private readonly data: MockStorageBucket;
 
diff --git a/packages/test-utils/src/testUtils/appWrappers.test.tsx b/packages/test-utils/src/testUtils/appWrappers.test.tsx
index 19c02c2158..464c547ecc 100644
--- a/packages/test-utils/src/testUtils/appWrappers.test.tsx
+++ b/packages/test-utils/src/testUtils/appWrappers.test.tsx
@@ -49,9 +49,6 @@ describe('wrapInTestApp', () => {
       expect.stringMatching(
         /^Warning: An update to %s inside a test was not wrapped in act\(...\)/,
       ),
-      expect.stringMatching(
-        /^Warning: An update to %s inside a test was not wrapped in act\(...\)/,
-      ),
     ]);
   });
 
diff --git a/packages/test-utils/src/testUtils/appWrappers.tsx b/packages/test-utils/src/testUtils/appWrappers.tsx
index 2e3a73e346..182de1ef63 100644
--- a/packages/test-utils/src/testUtils/appWrappers.tsx
+++ b/packages/test-utils/src/testUtils/appWrappers.tsx
@@ -24,7 +24,7 @@ import privateExports, {
 } from '@backstage/core-api';
 import { RenderResult } from '@testing-library/react';
 import { renderWithEffects } from '@backstage/test-utils-core';
-import { createMockApiRegistry } from './mockApiRegistry';
+import { mockApis } from './mockApis';
 
 const { PrivateAppImpl } = privateExports;
 
@@ -58,10 +58,9 @@ export function wrapInTestApp(
   options: TestAppOptions = {},
 ): ReactElement {
   const { routeEntries = ['/'] } = options;
-  const apis = createMockApiRegistry();
 
   const app = new PrivateAppImpl({
-    apis,
+    apis: [],
     components: {
       NotFoundErrorPage,
       BootErrorPage,
@@ -80,6 +79,7 @@ export function wrapInTestApp(
         variant: 'light',
       },
     ],
+    defaultApis: mockApis,
   });
 
   let Wrapper: ComponentType;
diff --git a/packages/test-utils/src/testUtils/mockApiRegistry.ts b/packages/test-utils/src/testUtils/mockApis.ts
similarity index 70%
rename from packages/test-utils/src/testUtils/mockApiRegistry.ts
rename to packages/test-utils/src/testUtils/mockApis.ts
index 15733ead88..e05a8e6cac 100644
--- a/packages/test-utils/src/testUtils/mockApiRegistry.ts
+++ b/packages/test-utils/src/testUtils/mockApis.ts
@@ -14,14 +14,14 @@
  * limitations under the License.
  */
 
-import { ApiTestRegistry } from '@backstage/core-api';
+import {
+  storageApiRef,
+  errorApiRef,
+  createApiFactory,
+} from '@backstage/core-api';
 import { MockErrorApi, MockStorageApi } from './apis';
 
-export function createMockApiRegistry(): ApiTestRegistry {
-  const registry = new ApiTestRegistry();
-
-  registry.register(MockErrorApi.factory);
-  registry.register(MockStorageApi.factory);
-
-  return registry;
-}
+export const mockApis = [
+  createApiFactory(errorApiRef, new MockErrorApi()),
+  createApiFactory(storageApiRef, MockStorageApi.create()),
+];