diff --git a/packages/reactivity/src/baseWatch.ts b/packages/reactivity/src/baseWatch.ts
index eea988798..2b1c64dd2 100644
--- a/packages/reactivity/src/baseWatch.ts
+++ b/packages/reactivity/src/baseWatch.ts
@@ -215,13 +215,13 @@ export function baseWatch(
       const _cb = cb
       cb = (...args) => {
         _cb(...args)
-        effect?.stop()
+        effect.stop()
       }
     } else {
       const _getter = getter
       getter = () => {
         _getter()
-        effect?.stop()
+        effect.stop()
       }
     }
   }
diff --git a/packages/runtime-core/src/componentOptions.ts b/packages/runtime-core/src/componentOptions.ts
index 8196a8239..be0b20f84 100644
--- a/packages/runtime-core/src/componentOptions.ts
+++ b/packages/runtime-core/src/componentOptions.ts
@@ -842,7 +842,9 @@ export function createWatcher(
   const options: WatchOptions = {}
   if (__COMPAT__) {
     const instance =
-      getCurrentScope() === currentInstance?.scope ? currentInstance : null
+      currentInstance && getCurrentScope() === currentInstance.scope
+        ? currentInstance
+        : null
 
     const newValue = getter()
     if (