diff --git a/packages/vue-i18n-core/src/i18n.ts b/packages/vue-i18n-core/src/i18n.ts
index 04209a68d..bb01e0481 100644
--- a/packages/vue-i18n-core/src/i18n.ts
+++ b/packages/vue-i18n-core/src/i18n.ts
@@ -1021,7 +1021,10 @@ function getComposer(
 ): Composer | null {
   let composer: Composer | null = null
   const root = target.root
-  let current: ComponentInternalInstance | null = target.parent
+  let current: ComponentInternalInstance | null = getParentComponentInstance(
+    target,
+    useComponent
+  )
   while (current != null) {
     const i18nInternal = i18n as unknown as I18nInternal
     if (i18n.mode === 'composition') {
@@ -1053,6 +1056,23 @@ function getComposer(
   return composer
 }
 
+function getParentComponentInstance(
+  target: ComponentInternalInstance | null,
+  useComponent = false
+) {
+  if (target == null) {
+    return null
+  }
+  if (!__BRIDGE__) {
+    // if `useComponent: true` will be specified, we get lexical scope owner instance for use-case slots
+    return !useComponent
+      ? target.parent
+      : (target.vnode as any).ctx || target.parent // eslint-disable-line @typescript-eslint/no-explicit-any
+  } else {
+    return target.parent
+  }
+}
+
 function setupLifeCycle(
   i18n: I18nInternal,
   target: ComponentInternalInstance,
diff --git a/packages/vue-i18n-core/test/components/Translation.test.ts b/packages/vue-i18n-core/test/components/Translation.test.ts
index fee7ab180..319a1e544 100644
--- a/packages/vue-i18n-core/test/components/Translation.test.ts
+++ b/packages/vue-i18n-core/test/components/Translation.test.ts
@@ -189,7 +189,7 @@ test('scope', async () => {
 `
   })
 
-  const Root = defineComponent({
+  const App = defineComponent({
     components: {
       Container
     },
@@ -208,7 +208,7 @@ test('scope', async () => {
     template: `<Container>`
   })
 
-  const wrapper = await mount(Root, i18n)
+  const wrapper = await mount(App, i18n)
 
   expect(wrapper.html()).toEqual(`this is rootthis is global`)
 })
diff --git a/packages/vue-i18n-core/test/issues.test.ts b/packages/vue-i18n-core/test/issues.test.ts
index e85162562..c58b84c19 100644
--- a/packages/vue-i18n-core/test/issues.test.ts
+++ b/packages/vue-i18n-core/test/issues.test.ts
@@ -18,7 +18,8 @@ import {
   h,
   withDirectives,
   resolveDirective,
-  nextTick
+  nextTick,
+  getCurrentInstance
 } from 'vue'
 import {
   setDevToolsHook,
@@ -32,6 +33,8 @@ import {
 import { createI18n, useI18n } from '../src/i18n'
 import { mount } from './helper'
 
+import type { ComponentOptions } from 'vue'
+
 const container = document.createElement('div')
 document.body.appendChild(container)
 
@@ -292,6 +295,92 @@ describe('issue #722', () => {
   })
 })
 
+test('issue #729', async () => {
+  const i18n = createI18n({
+    legacy: true,
+    locale: 'en',
+    messages
+  })
+
+  const C3 = defineComponent({
+    template: `<div>C3 slot: <slot></slot></div>`,
+    i18n: {
+      messages: {
+        en: {
+          hello: 'Hello {world} - C3',
+          world: 'world! - C3'
+        }
+      }
+    }
+  })
+
+  const C2 = defineComponent({
+    template: `<div>C2 slot: <slot></slot></div>`,
+    i18n: {
+      messages: {
+        en: {
+          goodbuy: 'Goodbuy!'
+        }
+      }
+    }
+  })
+
+  const C1 = defineComponent({
+    components: {
+      C2,
+      C3
+    },
+    template: `<div>
+	C1:
+	<div>{{ $t("hello", { world: $t("world") }) }}</div>
+	<i18n-t keypath="hello" tag="div">
+	  <template #world>
+	    <strong>{{ $t("world") }}</strong>
+	  </template>
+	</i18n-t>
+
+	<br />
+
+	<C2>
+	  <div>{{ $t("hello", { world: $t("world") }) }}</div>
+	  <i18n-t keypath="hello" tag="div">
+	    <template #world>
+	      <strong>{{ $t("world") }}</strong>
+	    </template>
+	  </i18n-t>
+	</C2>
+  <C3>
+    <div>{{ $t("hello", { world: $t("world") }) }}</div>
+    <i18n-t keypath="hello" tag="div">
+      <template #world>
+        <strong>{{ $t("world") }}</strong>
+      </template>
+    </i18n-t>
+  </C3>
+      </div>`,
+    i18n: {
+      messages: {
+        en: {
+          hello: 'Hello {world}',
+          world: 'world!'
+        }
+      }
+    }
+  })
+
+  const App = defineComponent({
+    components: {
+      C1
+    },
+    template: `<C1 />`
+  })
+  const wrapper = await mount(App, i18n)
+
+  expect(wrapper.html()).toEqual(
+    `<div> C1: <div>Hello world!</div><div>Hello <strong>world!</strong></div><br><div>C2 slot: <div>Hello world!</div><div>Hello <strong>world!</strong></div></div><div>C3 slot: <div>Hello world!</div><div>Hello <strong>world!</strong></div></div></div>`
+  )
+})
+
 test('issue #819: v-for', async () => {
   const i18n = createI18n({
     legacy: false,
@@ -722,3 +811,71 @@ test('issue #1123', async () => {
     `hello, <span>Hello</span>! Do you like <a><strong>Vue </strong> I18n </a>?`
   )
 })
+
+test('issue #1392', async () => {
+  const i18n = createI18n({
+    legacy: false,
+    locale: 'en',
+    messages: {
+      en: { hello: 'world' }
+    }
+  })
+
+  const Test = defineComponent({
+    setup() {
+      const instance = getCurrentInstance()
+      if (instance == null) {
+        throw new Error()
+      }
+      // emulate i18n custom block
+      const options = instance.type as ComponentOptions
+      options.__i18n = [
+        {
+          locale: 'en',
+          resource: {
+            any: 'thing'
+          }
+        }
+      ]
+      const { t } = useI18n()
+      return { t }
+    },
+    template: `<slot />`
+  })
+
+  const App = defineComponent({
+    components: {
+      Test
+    },
+    setup() {
+      const instance = getCurrentInstance()
+      if (instance == null) {
+        throw new Error()
+      }
+      // emulate i18n custom block
+      const options = instance.type as ComponentOptions
+      options.__i18n = [
+        {
+          locale: 'en',
+          resource: {
+            doesNotWork: 'works'
+          }
+        }
+      ]
+      const { t } = useI18n()
+
+      return { t }
+    },
+    template: `<div>
+  <Test>
+    component: <i18n-t keypath="doesNotWork" />
+    <br />
+    t: {{ t('doesNotWork') }}
+  </Test>
+</div>`
+  })
+
+  const wrapper = await mount(App, i18n)
+
+  expect(wrapper.html()).toEqual(`<div> component: works<br> t: works</div>`)
+})