diff --git a/lib/storage.js b/lib/storage.js
index 36dc224..59f0117 100644
--- a/lib/storage.js
+++ b/lib/storage.js
@@ -83,6 +83,9 @@ Storage.prototype._createIndexes = function() {
     copayerId: 1,
     txid: 1,
   });
+  this.db.collection(collections.SESSIONS).createIndex({
+    copayerId: 1
+  });
 };
 
 Storage.prototype.connect = function(opts, cb) {