diff --git a/lib/postgresql.js b/lib/postgresql.js
index 1b55e1d1..c850a51c 100644
--- a/lib/postgresql.js
+++ b/lib/postgresql.js
@@ -78,7 +78,6 @@ function PostgreSQL(postgresql, settings) {
     // pg-pool doesn't handle string config correctly
     this.clientConfig.connectionString = settings.url;
   }
-  this.clientConfig.Promise = Promise;
   this.pg = new postgresql.Pool(this.clientConfig);
   attachErrorHandler(settings, this.pg);