diff --git a/src/directive.js b/src/directive.js
index 5772d9541..77effe916 100644
--- a/src/directive.js
+++ b/src/directive.js
@@ -91,7 +91,11 @@ p._bind = function (def) {
       watcher.addCb(update)
     }
     this._watcher = watcher
-    this.update(watcher.value)
+    if (this._initValue != null) {
+      watcher.set(this._initValue)
+    } else {
+      this.update(watcher.value)
+    }
   }
   this._bound = true
 }
diff --git a/src/directives/model/checkbox.js b/src/directives/model/checkbox.js
index 2dbcfda73..450b31e4f 100644
--- a/src/directives/model/checkbox.js
+++ b/src/directives/model/checkbox.js
@@ -10,8 +10,7 @@ module.exports = {
     }
     _.on(el, 'change', this.listener)
     if (el.checked) {
-      // watcher is not set up yet
-      this.vm.$set(this.expression, el.checked)
+      this._initValue = el.checked
     }
   },
 
diff --git a/src/directives/model/radio.js b/src/directives/model/radio.js
index 5059f3fe6..99e881d7f 100644
--- a/src/directives/model/radio.js
+++ b/src/directives/model/radio.js
@@ -10,8 +10,7 @@ module.exports = {
     }
     _.on(el, 'change', this.listener)
     if (el.checked) {
-      // watcher is not set up yet
-      this.vm.$set(this.expression, el.value)
+      this._initValue = el.value
     }
   },
 
diff --git a/src/directives/model/select.js b/src/directives/model/select.js
index 067b641a8..e7264fcfc 100644
--- a/src/directives/model/select.js
+++ b/src/directives/model/select.js
@@ -124,7 +124,7 @@ function checkInitialValue () {
     }
   }
   if (initValue) {
-    this.vm.$set(this.expression, initValue)
+    this._initValue = initValue
   }
 }
 
diff --git a/src/directives/model/text.js b/src/directives/model/text.js
index d1d9e74b0..94aff5d12 100644
--- a/src/directives/model/text.js
+++ b/src/directives/model/text.js
@@ -99,8 +99,7 @@ module.exports = {
       el.hasAttribute('value') ||
       (el.tagName === 'TEXTAREA' && el.value.trim())
     ) {
-      // watcher is not set up yet
-      this.vm.$set(this.expression, el.value)
+      this._initValue = el.value
     }
   },