diff --git a/lib/postinstall.js b/lib/postinstall.js
index 34c3c00..553d640 100644
--- a/lib/postinstall.js
+++ b/lib/postinstall.js
@@ -19,8 +19,7 @@ function writeFabricServiceGradleHook() {
 var path = require("path");
 var fs = require("fs");
 module.exports = function($logger, $projectData, hookArgs) {
-  var platform = hookArgs.platform.toLowerCase();
-
+  var platform = (hookArgs.platform || (hookArgs.prepareData && hookArgs.prepareData.platform)).toLowerCase();
   function updateAppGradleScript(file) {
     var appBuildGradleContent = fs.readFileSync(file).toString();
     if (!appBuildGradleContent.match(/.*onesignal.*/)) {