diff --git a/orm/base.py b/orm/base.py
index 2925bb71..bd5e5717 100644
--- a/orm/base.py
+++ b/orm/base.py
@@ -9,12 +9,14 @@ from settings import DB_URL
 from orm._retry import RetryingQuery
 
 # engine = create_engine(DB_URL, convert_unicode=True, echo=False)
-engine = create_engine(connection_string,
-                                      pool_size=10,
-                                      max_overflow=2,
-                                      pool_recycle=300,
-                                      pool_pre_ping=True,
-                                      pool_use_lifo=True)
+engine = create_engine(DB_URL, 
+                        convert_unicode=True, 
+                        echo=False
+                        pool_size=10,
+                        max_overflow=2,
+                        pool_recycle=300,
+                        pool_pre_ping=True,
+                        pool_use_lifo=True)
 
 Session = sessionmaker(autocommit=False, autoflush=False, bind=engine, query_cls=RetryingQuery)
 #Session = sessionmaker(autocommit=False, autoflush=False, bind=engine)