diff --git a/jedi/evaluate/helpers.py b/jedi/evaluate/helpers.py
index ebe9b72b7..3ac409d83 100644
--- a/jedi/evaluate/helpers.py
+++ b/jedi/evaluate/helpers.py
@@ -46,9 +46,13 @@ def copy_node(obj):
         except AttributeError:
             pass
         else:
-            new_obj.names_dict = new_names_dict = {}
-            for string, names in names_dict.items():
-                new_names_dict[string] = [new_elements[n] for n in names]
+            try:
+                new_obj.names_dict = new_names_dict = {}
+            except AttributeError:  # Impossible to set CompFor.names_dict
+                pass
+            else:
+                for string, names in names_dict.items():
+                    new_names_dict[string] = [new_elements[n] for n in names]
         return new_obj
 
     if obj.type == 'name':
diff --git a/jedi/evaluate/representation.py b/jedi/evaluate/representation.py
index 943b485ef..423bc1fdb 100644
--- a/jedi/evaluate/representation.py
+++ b/jedi/evaluate/representation.py
@@ -610,9 +610,7 @@ def get_return_types(self, check_yields=False):
         return types
 
     def names_dicts(self, search_global):
-        yield dict((k, [self._copy_dict[v] for v in values])
-                   for k, values in self.base.names_dict.items())
-        #yield self.names_dict  # Replace with this!
+        yield self.names_dict
 
     @memoize_default(default=NO_DEFAULT)
     def _get_params(self):
diff --git a/jedi/parser/tree.py b/jedi/parser/tree.py
index 8ee9a239b..061423799 100644
--- a/jedi/parser/tree.py
+++ b/jedi/parser/tree.py
@@ -1193,10 +1193,6 @@ def names_dict(self):
             arr.append(name)
         return dct
 
-    @names_dict.setter
-    def names_dict(self, value):
-        pass
-
     def names_dicts(self, search_global):
         yield self.names_dict