diff --git a/jedi/helpers.py b/jedi/helpers.py
index b1fe2a62..0f6bd363 100644
--- a/jedi/helpers.py
+++ b/jedi/helpers.py
@@ -159,13 +159,15 @@ def fast_parent_copy(obj):
             # __dict__ not available, because of __slots__
             items = []
 
-        try:
-            names = new_obj.__slots__
-        except AttributeError:
-            # __slots__ not available (normal)
-            pass
-        else:
-            items += [(n, getattr(new_obj, n)) for n in names]
+        before = ()
+        for cls in new_obj.__class__.__mro__:
+            try:
+                if before == cls.__slots__:
+                    continue
+                before = cls.__slots__
+                items += [(n, getattr(new_obj, n)) for n in before]
+            except AttributeError:
+                pass
 
         for key, value in items:
             # replace parent (first try _parent and then parent)
diff --git a/jedi/parsing.py b/jedi/parsing.py
index 44c55f3d..fcda72ca 100644
--- a/jedi/parsing.py
+++ b/jedi/parsing.py
@@ -1192,7 +1192,7 @@ class Name(Simple):
     So a name like "module.class.function"
     would result in an array of [module, class, function]
     """
-    __slots__ = ('names', )
+    __slots__ = ('names',)
     def __init__(self, module, names, start_pos, end_pos, parent=None):
         super(Name, self).__init__(module, start_pos, end_pos)
         self.names = tuple(n if isinstance(n, NamePart) else