diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 3e0d81de39..c29e98ea45 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -4,6 +4,23 @@
 
 We really want Parse to be yours, to see it grow and thrive in the open source community.  
 
+##### Parse-server running on master
+
+Get started by cloning the [parser-server-example](https://github.com/parse-community/parse-server-example) repository and running `npm install` inside it. Update `parse-clients-config.json` inside the repo.
+
+Then add parse-server from master branch as a submodule
+
+```
+git submodule add https://github.com/parse-community/parse-server
+
+```
+
+Now link parse-server to use the repo instead of the package
+
+```
+npm link parse-server ./parse-server
+```
+
 ##### Please Do's
 
 * Take testing seriously! Aim to increase the test coverage with every pull request.
diff --git a/spec/PushController.spec.js b/spec/PushController.spec.js
index 1eb1607daf..e8956ee0d9 100644
--- a/spec/PushController.spec.js
+++ b/spec/PushController.spec.js
@@ -657,4 +657,38 @@ describe('PushController', () => {
       done();
     });
   });
+
+  it('sends push only when a deviceToken is set', (done) => {
+    var config = new Config(Parse.applicationId);
+    var auth = {
+      isMaster: true
+    }
+    var pushAdapter = {
+      send: function(body, installations) {
+        return successfulTransmissions(body, installations);
+      },
+      getValidPushTypes: function() {
+        return ["ios", "android"];
+      }
+    }
+
+    var pushController = new PushController();
+    const payload = {
+      data: {
+        alert: 'hello',
+      },
+      push_time: new Date().getTime()
+    }
+
+    reconfigureServer({
+      push: { adapter: pushAdapter }
+    }).then(() => {
+      return pushController.sendPush(payload, {}, config, auth);
+    }).then(() => {
+      done();
+    }, (err) => {
+      jfail(err);
+      done();
+    });
+  });
 });
diff --git a/src/Controllers/PushController.js b/src/Controllers/PushController.js
index 4e25b7ad52..eb5a707067 100644
--- a/src/Controllers/PushController.js
+++ b/src/Controllers/PushController.js
@@ -15,6 +15,11 @@ export class PushController {
     // Replace the expiration_time and push_time with a valid Unix epoch milliseconds time
     body.expiration_time = PushController.getExpirationTime(body);
     body.push_time = PushController.getPushTime(body);
+    // Intend to allow pushes only to valid installations
+    var hasDeviceToken = where.hasOwnProperty('deviceToken');
+    if (!hasDeviceToken) {
+      where["deviceToken"] = {"$exists":true};
+    }
     // TODO: If the req can pass the checking, we return immediately instead of waiting
     // pushes to be sent. We probably change this behaviour in the future.
     let badgeUpdate = () => {