diff --git a/packages/koishi-core/src/utils.ts b/packages/koishi-core/src/utils.ts
index 65bef0d7ba..fb1560dc5a 100644
--- a/packages/koishi-core/src/utils.ts
+++ b/packages/koishi-core/src/utils.ts
@@ -13,11 +13,11 @@ export function getSenderName (meta: MessageMeta) {
     : meta.sender ? meta.sender.card || meta.sender.nickname : userId
 }
 
-export function getTargetId (target: string) {
-  if (!target) return
+export function getTargetId (target: string | number) {
+  if (typeof target !== 'string' && typeof target !== 'number') return
   let qq = +target
   if (!qq) {
-    const capture = /\[CQ:at,qq=(\d+)\]/.exec(target)
+    const capture = /\[CQ:at,qq=(\d+)\]/.exec(target as any)
     if (capture) qq = +capture[1]
   }
   if (!isInteger(qq)) return
diff --git a/packages/koishi-core/tests/utils.spec.ts b/packages/koishi-core/tests/utils.spec.ts
index 79ec558cbb..bae7329cd7 100644
--- a/packages/koishi-core/tests/utils.spec.ts
+++ b/packages/koishi-core/tests/utils.spec.ts
@@ -46,6 +46,7 @@ describe('getTargetId', () => {
 
   test('wrong syntax', () => {
     expect(getTargetId('')).toBeFalsy()
+    expect(getTargetId(true as any)).toBeFalsy()
     expect(getTargetId('[CQ:at,qq=]')).toBeFalsy()
     expect(getTargetId('foo123')).toBeFalsy()
   })