diff --git a/packages/accounts-base/accounts_server.js b/packages/accounts-base/accounts_server.js
index dbffd61e64..b81dd40482 100644
--- a/packages/accounts-base/accounts_server.js
+++ b/packages/accounts-base/accounts_server.js
@@ -1260,9 +1260,9 @@ Ap.insertUserDoc = function (options, user) {
     // https://jira.mongodb.org/browse/SERVER-3069 will get fixed one day
     if (e.name !== 'MongoError') throw e;
     if (e.code !== 11000) throw e;
-    if (e.err.indexOf('emails.address') !== -1)
+    if (e.errmsg.indexOf('emails.address') !== -1)
       throw new Meteor.Error(403, "Email already exists.");
-    if (e.err.indexOf('username') !== -1)
+    if (e.errmsg.indexOf('username') !== -1)
       throw new Meteor.Error(403, "Username already exists.");
     // XXX better error reporting for services.facebook.id duplicate, etc
     throw e;