diff --git a/src/core/observer/watcher.js b/src/core/observer/watcher.js
index 1b1c0534c00..dd79bea1199 100644
--- a/src/core/observer/watcher.js
+++ b/src/core/observer/watcher.js
@@ -185,8 +185,7 @@ export default class Watcher {
         // Deep watchers and watchers on Object/Arrays should fire even
         // when the value is the same, because the value may
         // have mutated.
-        isObject(value) ||
-        this.deep
+        isObject(value)
       ) {
         // set new value
         const oldValue = this.value