diff --git a/src/__init__.py b/src/__init__.py
index e4799d9620da505320f15c4b6712e5456d132959..abc24f98d7e2a5c590e5d821cbe8a57151d3614c 100644
--- a/src/__init__.py
+++ b/src/__init__.py
@@ -53,6 +53,8 @@ class Record(object):
     will be individually derived from this class.
     """
 
+    __slots__ = []
+
     def __init__(self, valuedict=None, exclude=["self"], **kwargs):
         assert self.__class__ is not Record