diff --git a/backend/src/matrix.js b/backend/src/matrix.js
index 5539e29..53ccda2 100644
--- a/backend/src/matrix.js
+++ b/backend/src/matrix.js
@@ -6,6 +6,7 @@ const {
   SimpleFsStorageProvider,
 } = require('matrix-bot-sdk');
 const fastq = require('fastq');
+const Promise = require('bluebird');
 
 const {
   MATRIX_HOMESERVER_URL,