diff --git a/server/lib/models/transaction.js b/server/lib/models/transaction.js
index 2c85473..ae93b20 100644
--- a/server/lib/models/transaction.js
+++ b/server/lib/models/transaction.js
@@ -28,6 +28,7 @@ const TransactionSchema = new Schema({
 });
 
 TransactionSchema.index({ hash: 1 });
+TransactionSchema.index({ block: 1 });
 TransactionSchema.index({ 'outputs.address': 1 });
 TransactionSchema.index({ 'inputs.address': 1 });