diff --git a/integration/test/ParseObjectTest.js b/integration/test/ParseObjectTest.js
index 24285663c..e04c0ffdb 100644
--- a/integration/test/ParseObjectTest.js
+++ b/integration/test/ParseObjectTest.js
@@ -1774,4 +1774,55 @@ describe('Parse Object', () => {
     const fetched = await query.get(user.id);
     assert.equal(fetched.isDataAvailable(), true);
   });
+
+  it('retrieve subclass objects', async (done) => {
+    try {
+      class MySubclass extends Parse.Object {
+        constructor(attr) {
+          super('MySubclass', attr);
+          this.defaultProp = attr && attr.defaultProp || 'default';
+        }
+        get defaultProp() { return this.get('defaultProp'); }
+        set defaultProp(val) { this.set('defaultProp', val); }
+      }
+      Parse.Object.registerSubclass('MySubclass', MySubclass);
+
+      await new MySubclass({defaultProp: 'foo'}).save();
+      const result = await new Parse.Query(MySubclass).first();
+      expect(result.defaultProp).toBe('foo');
+
+      done();
+    } catch(e) {
+      done.fail(e);
+    }
+  });
+
+  it('conver from JSON', async (done) => {
+    try {
+
+      // Object without constructor
+      const o = Parse.Object.fromJSON({
+        className: 'FooObject',
+        name: 'foo'
+      }, true);
+
+      await o.save();
+      let result = await new Parse.Query('FooObject').first();
+      expect(result.get('name')).toBe('foo');
+
+      // Object with constructor `TestObject`
+      const to = Parse.Object.fromJSON({
+        className: 'TestObject',
+        name: 'foo'
+      }, true);
+
+      await to.save();
+      result = await new Parse.Query('TestObject').first();
+      expect(result.get('name')).toBe('foo');
+
+      done();
+    } catch(e) {
+      done.fail(e);
+    }
+  });
 });
diff --git a/integration/test/helper.js b/integration/test/helper.js
index df4355669..6cadddf7d 100644
--- a/integration/test/helper.js
+++ b/integration/test/helper.js
@@ -1,6 +1,6 @@
 const ParseServer = require('parse-server').ParseServer;
 
-jasmine.DEFAULT_TIMEOUT_INTERVAL = 5000;
+jasmine.DEFAULT_TIMEOUT_INTERVAL = 10000;
 beforeAll((done) => {
   const { app } = require('../server');
   const httpServer = require('http').createServer(app);
diff --git a/src/ParseObject.js b/src/ParseObject.js
index 3ae07cc78..eac833bef 100644
--- a/src/ParseObject.js
+++ b/src/ParseObject.js
@@ -1741,8 +1741,23 @@ class ParseObject {
     if (!json.className) {
       throw new Error('Cannot create an object without a className');
     }
+
     const constructor = classMap[json.className];
-    const o = constructor ? new constructor() : new ParseObject(json.className);
+
+    // Remove reserved fields
+    const attributes = {}
+    Object.assign({}, json);
+    if(constructor && constructor.readOnlyAttributes) {
+      constructor.readOnlyAttributes().forEach(attr => {
+        try { delete attributes[attr]; }
+        catch { 0; }
+      });
+    }
+    if(attributes && attributes.__type) delete attributes.__type;
+    if(attributes && attributes.className) delete attributes.className;
+
+    const o = constructor ? new constructor(attributes) : new ParseObject(json.className, attributes);
+
     const otherAttributes = {};
     for (const attr in json) {
       if (attr !== 'className' && attr !== '__type') {