diff --git a/packages/app-next/src/App.tsx b/packages/app-next/src/App.tsx
index ccfeb61b58..d7ec30bf95 100644
--- a/packages/app-next/src/App.tsx
+++ b/packages/app-next/src/App.tsx
@@ -17,7 +17,7 @@
 import React from 'react';
 import { createApp } from '@backstage/frontend-app-api';
 import { pagesPlugin } from './examples/pagesPlugin';
-import { CustomNotFoundErrorPage } from './examples/notFoundErrorPageExtension';
+import notFoundErrorPage from './examples/notFoundErrorPageExtension';
 import graphiqlPlugin from '@backstage/plugin-graphiql/alpha';
 import techRadarPlugin from '@backstage/plugin-tech-radar/alpha';
 import userSettingsPlugin from '@backstage/plugin-user-settings/alpha';
@@ -33,10 +33,7 @@ import {
 } from '@backstage/frontend-plugin-api';
 import techdocsPlugin from '@backstage/plugin-techdocs/alpha';
 import { homePage } from './HomePage';
-import {
-  collectLegacyComponents,
-  collectLegacyRoutes,
-} from '@backstage/core-compat-api';
+import { collectLegacyRoutes } from '@backstage/core-compat-api';
 import { FlatRoutes } from '@backstage/core-app-api';
 import { Route } from 'react-router';
 import { CatalogImportPage } from '@backstage/plugin-catalog-import';
@@ -118,10 +115,6 @@ const collectedLegacyPlugins = collectLegacyRoutes(
   </FlatRoutes>,
 );
 
-const legacyAppComponents = collectLegacyComponents({
-  NotFoundErrorPage: CustomNotFoundErrorPage,
-});
-
 const app = createApp({
   features: [
     graphiqlPlugin,
@@ -137,7 +130,7 @@ const app = createApp({
         scmAuthExtension,
         scmIntegrationApi,
         signInPage,
-        ...legacyAppComponents,
+        notFoundErrorPage,
       ],
     }),
   ],
diff --git a/packages/app-next/src/examples/notFoundErrorPageExtension.tsx b/packages/app-next/src/examples/notFoundErrorPageExtension.tsx
index 82acc25fb5..6cdaff978f 100644
--- a/packages/app-next/src/examples/notFoundErrorPageExtension.tsx
+++ b/packages/app-next/src/examples/notFoundErrorPageExtension.tsx
@@ -36,15 +36,9 @@ export function CustomNotFoundErrorPage() {
     >
       <Typography variant="h1">404</Typography>
       <Typography color="textSecondary" paragraph style={{ width: 300 }}>
-        Bowie was unable to locate this page. Please contact your support team
-        if this page used to exist.
+        Unable to locate this page. Please contact your support team if this
+        page used to exist.
       </Typography>
-      <img
-        alt="Backstage bowie"
-        src="https://info.backstage.spotify.com/hs-fs/hubfs/Call%20Bowie%202.png"
-        width="200"
-        style={{ filter: 'grayscale(50%)' }}
-      />
       <Button
         variant="contained"
         to="/"
diff --git a/packages/core-compat-api/api-report.md b/packages/core-compat-api/api-report.md
index 93a2fa8cf1..877aefa24f 100644
--- a/packages/core-compat-api/api-report.md
+++ b/packages/core-compat-api/api-report.md
@@ -6,9 +6,7 @@
 /// <reference types="react" />
 
 import { AnyRouteRefParams } from '@backstage/core-plugin-api';
-import { AppComponents } from '@backstage/core-plugin-api';
 import { BackstagePlugin } from '@backstage/frontend-plugin-api';
-import { ExtensionDefinition } from '@backstage/frontend-plugin-api';
 import { ExtensionOverrides } from '@backstage/frontend-plugin-api';
 import { ExternalRouteRef } from '@backstage/core-plugin-api';
 import { ExternalRouteRef as ExternalRouteRef_2 } from '@backstage/frontend-plugin-api';
@@ -18,11 +16,6 @@ import { RouteRef as RouteRef_2 } from '@backstage/frontend-plugin-api';
 import { SubRouteRef } from '@backstage/core-plugin-api';
 import { SubRouteRef as SubRouteRef_2 } from '@backstage/frontend-plugin-api';
 
-// @public (undocumented)
-export function collectLegacyComponents(
-  components: Partial<AppComponents>,
-): ExtensionDefinition<unknown>[];
-
 // @public (undocumented)
 export function collectLegacyRoutes(
   flatRoutesElement: JSX.Element,
diff --git a/packages/core-compat-api/src/collectLegacyComponents.test.tsx b/packages/core-compat-api/src/collectLegacyComponents.test.tsx
deleted file mode 100644
index 7ca11a777e..0000000000
--- a/packages/core-compat-api/src/collectLegacyComponents.test.tsx
+++ /dev/null
@@ -1,66 +0,0 @@
-/*
- * Copyright 2023 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import React from 'react';
-
-import { collectLegacyComponents } from './collectLegacyComponents';
-
-describe('collectLegacyComponents', () => {
-  const components = {
-    Progress: () => <div>Progress</div>,
-    BootErrorPage: () => <div>BootErrorPage</div>,
-    NotFoundErrorPage: () => <div>NotFoundErrorPage</div>,
-    ErrorBoundaryFallback: () => <div>ErrorBoundaryFallback</div>,
-  };
-
-  it('should collect legacy routes', () => {
-    const collected = collectLegacyComponents(components);
-
-    expect(
-      collected.map(p => ({
-        kind: p.kind,
-        namespace: p.namespace,
-        attachTo: p.attachTo,
-        disabled: p.disabled,
-      })),
-    ).toEqual([
-      {
-        kind: 'component',
-        namespace: 'core.components.progress',
-        attachTo: { id: 'core', input: 'components' },
-        disabled: false,
-      },
-      {
-        kind: 'component',
-        namespace: 'core.components.bootErrorPage',
-        attachTo: { id: 'core', input: 'components' },
-        disabled: false,
-      },
-      {
-        kind: 'component',
-        namespace: 'core.components.notFoundErrorPage',
-        attachTo: { id: 'core', input: 'components' },
-        disabled: false,
-      },
-      {
-        kind: 'component',
-        namespace: 'core.components.errorBoundaryFallback',
-        attachTo: { id: 'core', input: 'components' },
-        disabled: false,
-      },
-    ]);
-  });
-});
diff --git a/packages/core-compat-api/src/collectLegacyComponents.tsx b/packages/core-compat-api/src/collectLegacyComponents.tsx
deleted file mode 100644
index 6ae6df7cff..0000000000
--- a/packages/core-compat-api/src/collectLegacyComponents.tsx
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright 2023 The Backstage Authors
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- *     http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
- */
-
-import {
-  ComponentRef,
-  createComponentExtension,
-  coreComponentsRefs,
-  ExtensionDefinition,
-} from '@backstage/frontend-plugin-api';
-import { AppComponents } from '@backstage/core-plugin-api';
-
-type ComponentTypes<T = AppComponents> = T[keyof T];
-
-const refs: Record<string, ComponentRef<ComponentTypes>> = {
-  Progress: coreComponentsRefs.progress,
-  BootErrorPage: coreComponentsRefs.bootErrorPage,
-  NotFoundErrorPage: coreComponentsRefs.notFoundErrorPage,
-  ErrorBoundaryFallback: coreComponentsRefs.errorBoundaryFallback,
-};
-
-/** @public */
-export function collectLegacyComponents(components: Partial<AppComponents>) {
-  return Object.entries(components).reduce<ExtensionDefinition<unknown>[]>(
-    (extensions, [name, component]) => {
-      const ref = refs[name];
-      return ref
-        ? extensions.concat(
-            createComponentExtension({
-              ref,
-              component: { sync: () => component },
-            }),
-          )
-        : extensions;
-    },
-    [],
-  );
-}
diff --git a/packages/core-compat-api/src/index.ts b/packages/core-compat-api/src/index.ts
index d31513e559..421ced7054 100644
--- a/packages/core-compat-api/src/index.ts
+++ b/packages/core-compat-api/src/index.ts
@@ -14,6 +14,5 @@
  * limitations under the License.
  */
 export { collectLegacyRoutes } from './collectLegacyRoutes';
-export { collectLegacyComponents } from './collectLegacyComponents';
 export { convertLegacyApp } from './convertLegacyApp';
 export { convertLegacyRouteRef } from './convertLegacyRouteRef';