diff --git a/server/migrations/20170827182423-improve-references.js b/server/migrations/20170827182423-improve-references.js
index 788f3b60..a8bd04df 100644
--- a/server/migrations/20170827182423-improve-references.js
+++ b/server/migrations/20170827182423-improve-references.js
@@ -1,5 +1,6 @@
 module.exports = {
   up: async function(queryInterface, Sequelize) {
+    await queryInterface.removeIndex('documents', 'atlasId_foreign_idx');
     await queryInterface.changeColumn('documents', 'atlasId', {
       type: Sequelize.UUID,
       allowNull: true,