diff --git a/packages/runtime-core/__tests__/rendererAttrsFallthrough.spec.ts b/packages/runtime-core/__tests__/rendererAttrsFallthrough.spec.ts
index 1de05b67b44..5e885a3d59c 100644
--- a/packages/runtime-core/__tests__/rendererAttrsFallthrough.spec.ts
+++ b/packages/runtime-core/__tests__/rendererAttrsFallthrough.spec.ts
@@ -13,6 +13,8 @@ import {
   defineComponent,
   openBlock,
   createBlock,
+  createElementVNode,
+  createElementBlock,
   FunctionalComponent,
   createCommentVNode,
   Fragment,
@@ -673,6 +675,58 @@ describe('attribute fallthrough', () => {
     expect(click).toHaveBeenCalled()
   })
 
+  it('should support fallthrough for nested fragments', async () => {
+    const toggle = ref(false)
+
+    const Child = {
+      setup() {
+        return () => (
+          openBlock(),
+          createElementBlock(
+            Fragment,
+            null,
+            [
+              createCommentVNode(' comment A '),
+              toggle.value
+                ? (openBlock(), createElementBlock('span', { key: 0 }, 'Foo'))
+                : (openBlock(),
+                  createElementBlock(
+                    Fragment,
+                    { key: 1 },
+                    [
+                      createCommentVNode(' comment B '),
+                      createElementVNode('div', null, 'Bar')
+                    ],
+                    PatchFlags.STABLE_FRAGMENT | PatchFlags.DEV_ROOT_FRAGMENT
+                  ))
+            ],
+            PatchFlags.STABLE_FRAGMENT | PatchFlags.DEV_ROOT_FRAGMENT
+          )
+        )
+      }
+    }
+
+    const Root = {
+      setup() {
+        return () => (openBlock(), createBlock(Child, { class: 'red' }))
+      }
+    }
+
+    const root = document.createElement('div')
+    document.body.appendChild(root)
+    render(h(Root), root)
+
+    expect(root.innerHTML).toBe(
+      `<!-- comment A --><!-- comment B --><div class="red">Bar</div>`
+    )
+
+    toggle.value = true
+    await nextTick()
+    expect(root.innerHTML).toBe(
+      `<!-- comment A --><span class=\"red\">Foo</span>`
+    )
+  })
+
   // #1989
   it('should not fallthrough v-model listeners with corresponding declared prop', () => {
     let textFoo = ''
diff --git a/packages/runtime-core/src/componentRenderUtils.ts b/packages/runtime-core/src/componentRenderUtils.ts
index d9de968a074..d39ca5d1af3 100644
--- a/packages/runtime-core/src/componentRenderUtils.ts
+++ b/packages/runtime-core/src/componentRenderUtils.ts
@@ -12,7 +12,8 @@ import {
   cloneVNode,
   VNodeArrayChildren,
   isVNode,
-  blockStack
+  blockStack,
+  Fragment
 } from './vnode'
 import { handleError, ErrorCodes } from './errorHandling'
 import { PatchFlags, ShapeFlags, isOn, isModelListener } from '@vue/shared'
@@ -255,6 +256,11 @@ const getChildRoot = (vnode: VNode): [VNode, SetRootFn] => {
   if (!childRoot) {
     return [vnode, undefined]
   }
+
+  if (childRoot.type === Fragment) {
+    return getChildRoot(childRoot)
+  }
+
   const index = rawChildren.indexOf(childRoot)
   const dynamicIndex = dynamicChildren ? dynamicChildren.indexOf(childRoot) : -1
   const setRoot: SetRootFn = (updatedRoot: VNode) => {