diff --git a/projects/forms/src/internal/controllers/state-disabled.controller.test.ts b/projects/forms/src/internal/controllers/state-disabled.controller.test.ts
index 87a4b3312..b0f82eaf9 100644
--- a/projects/forms/src/internal/controllers/state-disabled.controller.test.ts
+++ b/projects/forms/src/internal/controllers/state-disabled.controller.test.ts
@@ -11,7 +11,7 @@ import type { ReactiveController } from './types.js';
 class StateDisabledControllerTestElement extends HTMLElement {
   static formAssociated = true;
 
-  disabled = false;
+  disabled: boolean | null | undefined = false;
   readOnly = false;
   _internals?: ElementInternals;
   #controllers = new Set<ReactiveController>();
@@ -75,4 +75,22 @@ describe('StateDisabledController', () => {
     expect(element._internals!.ariaDisabled).toBe(null);
     expect(element.matches(':state(disabled)')).toBe(true);
   });
+
+  it('should clear aria-disabled when disabled is unset', () => {
+    element.disabled = true;
+    element.sync();
+    expect(element._internals!.ariaDisabled).toBe('true');
+
+    element.disabled = undefined;
+    element.sync();
+
+    expect(element._internals!.ariaDisabled).toBe(null);
+    expect(element.matches(':state(disabled)')).toBe(false);
+
+    element.disabled = null;
+    element.sync();
+
+    expect(element._internals!.ariaDisabled).toBe(null);
+    expect(element.matches(':state(disabled)')).toBe(false);
+  });
 });