diff --git a/bigchaindb/backend/exceptions.py b/bigchaindb/backend/exceptions.py
index 1f7c57a7..41bac0c6 100644
--- a/bigchaindb/backend/exceptions.py
+++ b/bigchaindb/backend/exceptions.py
@@ -4,5 +4,6 @@ from bigchaindb.exceptions import BigchainDBError
 class ConnectionError(BigchainDBError):
     """Exception raised when the connection to the DataBase fails."""
 
+
 class DatabaseOpFailedError(BigchainDBError):
     """Exception for database operation errors."""