diff --git a/packages/frontend-app-api/src/tree/readAppExtensionsConfig.test.ts b/packages/frontend-app-api/src/tree/readAppExtensionsConfig.test.ts
index 91f6992f29..d291df7384 100644
--- a/packages/frontend-app-api/src/tree/readAppExtensionsConfig.test.ts
+++ b/packages/frontend-app-api/src/tree/readAppExtensionsConfig.test.ts
@@ -105,7 +105,7 @@ describe('readAppExtensionsConfig', () => {
           app: {
             extensions: [
               {
-                'core.router/routes': {
+                '': {
                   extension: 'example-package#MyPage',
                   config: { foo: 'bar' },
                 },
@@ -115,7 +115,7 @@ describe('readAppExtensionsConfig', () => {
         }),
       ),
     ).toThrowErrorMatchingInlineSnapshot(
-      `"Invalid extension configuration at app.extensions[0], extension ID must not contain slashes; got 'core.router/routes', did you mean 'core.router'?"`,
+      `"Invalid extension configuration at app.extensions[0], extension ID must not be empty or contain whitespace"`,
     );
   });
 });
@@ -166,9 +166,6 @@ describe('expandShorthandExtensionParameters', () => {
     expect(() => run(' a')).toThrowErrorMatchingInlineSnapshot(
       `"Invalid extension configuration at app.extensions[1], extension ID must not be empty or contain whitespace"`,
     );
-    expect(() => run('core.router/routes')).toThrowErrorMatchingInlineSnapshot(
-      `"Invalid extension configuration at app.extensions[1], extension ID must not contain slashes; got 'core.router/routes', did you mean 'core.router'?"`,
-    );
   });
 
   it('supports null value', () => {
diff --git a/packages/frontend-app-api/src/tree/readAppExtensionsConfig.ts b/packages/frontend-app-api/src/tree/readAppExtensionsConfig.ts
index 2b5b51ce92..cca7064add 100644
--- a/packages/frontend-app-api/src/tree/readAppExtensionsConfig.ts
+++ b/packages/frontend-app-api/src/tree/readAppExtensionsConfig.ts
@@ -70,15 +70,6 @@ export function expandShorthandExtensionParameters(
         errorMsg('extension ID must not be empty or contain whitespace'),
       );
     }
-
-    if (id.includes('/')) {
-      let message = `extension ID must not contain slashes; got '${id}'`;
-      const good = id.split('/')[0];
-      if (good) {
-        message += `, did you mean '${good}'?`;
-      }
-      throw new Error(errorMsg(message));
-    }
   }
 
   // Example YAML: