diff --git a/www/common/sframe-boot2.js b/www/common/sframe-boot2.js
index 818e3b0a0..fe614ba33 100644
--- a/www/common/sframe-boot2.js
+++ b/www/common/sframe-boot2.js
@@ -13,6 +13,11 @@ define([
         };
     }
 
+    // RPC breaks if you don't support Number.MAX_SAFE_INTEGER
+    if (Number && !Number.MAX_SAFE_INTEGER) {
+        Number.MAX_SAFE_INTEGER = 9007199254740991;
+    }
+
     var mkFakeStore = function () {
         var fakeStorage = {
             getItem: function (k) { return fakeStorage[k]; },