diff --git a/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.spec.tsx b/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.spec.tsx
index 873dbb8738a..1a0a1dfa213 100644
--- a/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.spec.tsx
+++ b/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.spec.tsx
@@ -56,6 +56,30 @@ const TestedComponent = ({ role }) => {
     );
 };
 
+const TestedComponentReturningNull = ({ role }) => {
+    const history = createMemoryHistory();
+
+    return (
+        <CoreAdminContext history={history}>
+            <CoreAdminRoutes
+                layout={MyLayout}
+                catchAll={CatchAll}
+                loading={Loading}
+            >
+                <Resource name="posts" />
+                <Resource name="comments" />
+                {() =>
+                    role === 'admin'
+                        ? [<Resource name="user" />, <Resource name="admin" />]
+                        : role === 'user'
+                        ? [<Resource name="user" />]
+                        : null
+                }
+            </CoreAdminRoutes>
+        </CoreAdminContext>
+    );
+};
+
 const ResourceWithPermissions = (props: ResourceProps) => (
     <Resource {...props} />
 );
@@ -168,6 +192,12 @@ describe('useConfigureAdminRouterFromChildren', () => {
         expectResource('user').not.toBeNull();
         expectResource('admin').not.toBeNull();
     });
+    it('should accept function returning null', async () => {
+        render(<TestedComponentReturningNull role="admin" />);
+        await waitFor(() => expect(screen.queryByText('Loading')).toBeNull());
+        expectResource('user').not.toBeNull();
+        expectResource('admin').not.toBeNull();
+    });
     it('should call registerResource with the permissions', async () => {
         render(<TestedComponentWithPermissions />);
         await waitFor(() => expect(screen.queryByText('Loading')).toBeNull());
diff --git a/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.tsx b/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.tsx
index 707167da7a7..8147c20598a 100644
--- a/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.tsx
+++ b/packages/ra-core/src/core/useConfigureAdminRouterFromChildren.tsx
@@ -97,7 +97,7 @@ const useRoutesAndResourcesFromChildren = (
         ) => {
             try {
                 const childrenFuncResult = childFunc(permissions);
-                if ((childrenFuncResult as Promise<ReactNode>).then) {
+                if ((childrenFuncResult as Promise<ReactNode>)?.then) {
                     (childrenFuncResult as Promise<ReactNode>).then(
                         resolvedChildren => {
                             mergeRoutesAndResources(