diff --git a/packages/runtime-vapor/__tests__/componentEmits.spec.ts b/packages/runtime-vapor/__tests__/componentEmits.spec.ts
index 7c3bfe69ed4..8c8a56085ba 100644
--- a/packages/runtime-vapor/__tests__/componentEmits.spec.ts
+++ b/packages/runtime-vapor/__tests__/componentEmits.spec.ts
@@ -195,8 +195,17 @@ describe('component: emit', () => {
     ).not.toHaveBeenWarned()
   })
 
-  test.todo('validator warning', () => {
-    // TODO: warning validator
+  test('validator warning', () => {
+    define({
+      emits: {
+        foo: (arg: number) => arg > 0,
+      },
+      setup(_, { emit }) {
+        emit('foo', -1)
+        return []
+      },
+    }).render()
+    expect(`event validation failed for event "foo"`).toHaveBeenWarned()
   })
 
   test('.once', () => {
@@ -415,8 +424,4 @@ describe('component: emit', () => {
     await nextTick()
     expect(fn).not.toHaveBeenCalled()
   })
-
-  // NOTE: not supported mixins
-  // test.todo('merge string array emits', async () => {})
-  // test.todo('merge object emits', async () => {})
 })
diff --git a/packages/runtime-vapor/src/componentEmits.ts b/packages/runtime-vapor/src/componentEmits.ts
index f26c6813505..60007037ef3 100644
--- a/packages/runtime-vapor/src/componentEmits.ts
+++ b/packages/runtime-vapor/src/componentEmits.ts
@@ -18,7 +18,7 @@ export function normalizeEmitsOptions(
   let normalized: ObjectEmitsOptions
   if (isArray(raw)) {
     normalized = {}
-    for (const key in raw) normalized[key] = null
+    for (const key of raw) normalized[key] = null
   } else {
     normalized = raw
   }