diff --git a/packages/runtime-core/src/apiWatch.ts b/packages/runtime-core/src/apiWatch.ts
index b3c92239..da3df303 100644
--- a/packages/runtime-core/src/apiWatch.ts
+++ b/packages/runtime-core/src/apiWatch.ts
@@ -14,7 +14,8 @@ import {
   isFunction,
   isString,
   hasChanged,
-  NOOP
+  NOOP,
+  remove
 } from '@vue/shared'
 import {
   currentInstance,
@@ -264,11 +265,7 @@ function doWatch(
   return () => {
     stop(runner)
     if (instance) {
-      const effects = instance.effects!
-      const index = effects.indexOf(runner)
-      if (index > -1) {
-        effects.splice(index, 1)
-      }
+      remove(instance.effects!, runner)
     }
   }
 }
diff --git a/packages/runtime-core/src/components/KeepAlive.ts b/packages/runtime-core/src/components/KeepAlive.ts
index d5750d5a..8aae9b4e 100644
--- a/packages/runtime-core/src/components/KeepAlive.ts
+++ b/packages/runtime-core/src/components/KeepAlive.ts
@@ -10,7 +10,7 @@ import {
 import { VNode, cloneVNode, isVNode, VNodeProps } from '../vnode'
 import { warn } from '../warning'
 import { onBeforeUnmount, injectHook, onUnmounted } from '../apiLifecycle'
-import { isString, isArray, ShapeFlags } from '@vue/shared'
+import { isString, isArray, ShapeFlags, remove } from '@vue/shared'
 import { watch } from '../apiWatch'
 import { SuspenseBoundary } from './Suspense'
 import {
@@ -297,7 +297,6 @@ function injectToKeepAliveRoot(
 ) {
   injectHook(type, hook, keepAliveRoot, true /* prepend */)
   onUnmounted(() => {
-    const hooks = keepAliveRoot[type]!
-    hooks.splice(hooks.indexOf(hook), 1)
+    remove(keepAliveRoot[type]!, hook)
   }, target)
 }
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
index b08300cd..d5c35614 100644
--- a/packages/shared/src/index.ts
+++ b/packages/shared/src/index.ts
@@ -36,6 +36,13 @@ export const extend = <T extends object, U extends object>(
   return a as any
 }
 
+export const remove = <T>(arr: T[], el: T) => {
+  const i = arr.indexOf(el)
+  if (i > -1) {
+    arr.splice(i, 1)
+  }
+}
+
 const hasOwnProperty = Object.prototype.hasOwnProperty
 export const hasOwn = (
   val: object,