diff --git a/src/core/instance/state.js b/src/core/instance/state.js
index 326f7f36bf7..34cd9690e5b 100644
--- a/src/core/instance/state.js
+++ b/src/core/instance/state.js
@@ -86,7 +86,7 @@ function initProps (vm: Component, propsOptions: Object) {
         )
       }
       defineReactive(props, key, value, () => {
-        if (vm.$parent && !isUpdatingChildComponent) {
+        if (!isRoot && !isUpdatingChildComponent) {
           warn(
             `Avoid mutating a prop directly since the value will be ` +
             `overwritten whenever the parent component re-renders. ` +