diff --git a/jedi/evaluate/compiled/fake.py b/jedi/evaluate/compiled/fake.py
index 045f0c8b..d9d22856 100644
--- a/jedi/evaluate/compiled/fake.py
+++ b/jedi/evaluate/compiled/fake.py
@@ -103,10 +103,8 @@ def get_faked(module, obj, name=None):
     if not isinstance(result, Class) and result is not None:
         # Set the docstr which was previously not set (faked modules don't
         # contain it).
-        result.docstr = None
-        if obj.__doc__:
-            doc = '''"""%s"""''' % obj.__doc__  # TODO need escapes.
-            result.docstr = tokenize.Token(tokenize.STRING, doc, (0, 0))
+        doc = '''"""%s"""''' % obj.__doc__  # TODO need escapes.
+        result.add_docstr(tokenize.Token(tokenize.STRING, doc, (0, 0)))
         return result
 
 
diff --git a/jedi/parser/representation.py b/jedi/parser/representation.py
index 90041dcb..7757310e 100644
--- a/jedi/parser/representation.py
+++ b/jedi/parser/representation.py
@@ -182,7 +182,7 @@ class Simple(Base):
 
 
 class IsScope(Base):
-    pass
+    __slots__ = ()
 
 
 class Scope(Simple, IsScope, DocstringMixin):