diff --git a/goblin/api.py b/goblin/api.py
index 39117f2ec62db2bc6e92cc58d0e0bd6bb001604f..e920ff98fc5ca45fc0c75b2ca3dbd7c50a929388 100644
--- a/goblin/api.py
+++ b/goblin/api.py
@@ -272,12 +272,10 @@ class Edge(meta.Element):
 
 class VertexProperty(meta.Element, abc.BaseProperty):
 
-    __data_type__ = None
-
     def __init__(self, data_type, *, value=None, default=None):
         if isinstance(data_type, type):
             data_type = data_type()
-        self.__data_type__ = data_type
+        self._data_type = data_type
         self._value = value
         self._default = default
 
@@ -287,7 +285,7 @@ class VertexProperty(meta.Element, abc.BaseProperty):
 
     @property
     def data_type(self):
-        return self.__data_type__
+        return self._data_type
 
     @property
     def value(self):
diff --git a/goblin/properties.py b/goblin/properties.py
index abbdd626f5acbdfd0084442a859f3c3fe007e094..ab74549bda364086aa5d108cda7923830d5e52b2 100644
--- a/goblin/properties.py
+++ b/goblin/properties.py
@@ -68,8 +68,6 @@ class Property(abc.BaseProperty):
     """API class used to define properties. Replaced with
       :py:class:`PropertyDescriptor` by :py:class:`api.ElementMeta`."""
 
-    descriptor = PropertyDescriptor
-
     def __init__(self, data_type, *, default=None):
         if isinstance(data_type, type):
             data_type = data_type()