diff --git a/mongo.js b/mongo.js
index 6059d70..3cfd3eb 100644
--- a/mongo.js
+++ b/mongo.js
@@ -36,7 +36,7 @@ const schemas = {
 const Histories = mongoose.model('histories', schemas.histories)
 const Metadata = mongoose.model('metadata', schemas.metadata)
 
-mongoose.connect(config.mongoUrl, { useNewUrlParser: true, useUnifiedTopology: true })
+mongoose.connect(config.mongoUrl, { useNewUrlParser: true, useUnifiedTopology: true, debug: true })
 
 const db = mongoose.connection
 db.on('error', console.error.bind(console, 'connection error:'))