diff --git a/build/tasks/build-task.coffee b/build/tasks/build-task.coffee
index 9098e5259..a86c7c1f4 100644
--- a/build/tasks/build-task.coffee
+++ b/build/tasks/build-task.coffee
@@ -90,9 +90,6 @@ module.exports = (grunt) ->
       path.join('snippets', 'node_modules', 'pegjs')
       path.join('snippets', 'node_modules', '.bin', 'pegjs')
 
-      # These aren't needed since WeakMap is built-in
-      path.join('property-accessors', 'node_modules', 'es6-weak-map')
-
       '.DS_Store'
       '.jshintrc'
       '.npmignore'
diff --git a/package.json b/package.json
index 872d15634..52210a81d 100644
--- a/package.json
+++ b/package.json
@@ -37,7 +37,6 @@
     "nslog": "^2.0.0",
     "oniguruma": "^4.2.4",
     "pathwatcher": "^5.0.0",
-    "property-accessors": "^1.1.3",
     "random-words": "0.0.1",
     "runas": "2.0.0",
     "scandal": "2.1.2",
diff --git a/src/model.coffee b/src/model.coffee
index 1cea87665..94c06a76f 100644
--- a/src/model.coffee
+++ b/src/model.coffee
@@ -1,11 +1,7 @@
-PropertyAccessors = require 'property-accessors'
-
 nextInstanceId = 1
 
 module.exports =
 class Model
-  PropertyAccessors.includeInto(this)
-
   @resetNextInstanceId: -> nextInstanceId = 1
 
   alive: true
@@ -15,9 +11,7 @@ class Model
 
   assignId: (id) ->
     @id ?= id ? nextInstanceId++
-
-  @::advisedAccessor 'id',
-    set: (id) -> nextInstanceId = id + 1 if id >= nextInstanceId
+    nextInstanceId = id + 1 if id >= nextInstanceId
 
   destroy: ->
     return unless @isAlive()