Use meteor-babel-helpers package in babel-runtime.

packages/babel-runtime/.npm/package/npm-shrinkwrap.json

@@ -1,5 +1,10 @@
 {
   "dependencies": {
+    "meteor-babel-helpers": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/meteor-babel-helpers/-/meteor-babel-helpers-0.0.3.tgz",
+      "from": "meteor-babel-helpers@0.0.3"
+    },
     "regenerator": {
       "version": "0.8.42",
       "resolved": "https://registry.npmjs.org/regenerator/-/regenerator-0.8.42.tgz",

packages/babel-runtime/babel-runtime.js

@@ -2,49 +2,7 @@ var hasOwn = Object.prototype.hasOwnProperty;
 var S = typeof Symbol === "function" ? Symbol : {};
 var iteratorSymbol = S.iterator || "@@iterator";
 
-function canDefineNonEnumerableProperties() {
-  var testObj = {};
-  var testPropName = "t";
-
-  try {
-    Object.defineProperty(testObj, testPropName, {
-      enumerable: false,
-      value: testObj
-    });
-
-    for (var k in testObj) {
-      if (k === testPropName) {
-        return false;
-      }
-    }
-  } catch (e) {
-    return false;
-  }
-
-  return testObj[testPropName] === testObj;
-}
-
-meteorBabelHelpers = {
-  // Meteor-specific runtime helper for wrapping the object of for-in
-  // loops, so that inherited Array methods defined by es5-shim can be
-  // ignored in browsers where they cannot be defined as non-enumerable.
-  sanitizeForInObject: canDefineNonEnumerableProperties()
-    ? function (value) { return value; }
-    : function (obj) {
-      if (Array.isArray(obj)) {
-        var newObj = {};
-        var keys = Object.keys(obj);
-        var keyCount = keys.length;
-        for (var i = 0; i < keyCount; ++i) {
-          var key = keys[i];
-          newObj[key] = obj[key];
-        }
-        return newObj;
-      }
-
-      return obj;
-    }
-};
+meteorBabelHelpers = require("meteor-babel-helpers");
 
 var BabelRuntime = {
   // es6.templateLiterals

packages/babel-runtime/package.js

@@ -6,7 +6,8 @@ Package.describe({
 });
 
 Npm.depends({
-  regenerator: "0.8.42"
+  regenerator: "0.8.42",
+  "meteor-babel-helpers": "0.0.3"
 });
 
 Package.onUse(function (api) {