diff --git a/jedi/cache.py b/jedi/cache.py
index 6d72b675..ce710865 100644
--- a/jedi/cache.py
+++ b/jedi/cache.py
@@ -149,16 +149,15 @@ def underscore_memoization(func):
     return wrapper
 
 
-def memoize(func):
+def memoize_method(method):
     """A normal memoize function."""
-    dct = {}
-
-    def wrapper(*args, **kwargs):
+    def wrapper(self, *args, **kwargs):
+        dct = self.__dict__.setdefault('_memoize_method_dct', {})
         key = (args, frozenset(kwargs.items()))
         try:
             return dct[key]
         except KeyError:
-            result = func(*args, **kwargs)
+            result = method(self, *args, **kwargs)
             dct[key] = result
             return result
     return wrapper
diff --git a/jedi/evaluate/compiled/__init__.py b/jedi/evaluate/compiled/__init__.py
index b5402e28..2eb876bb 100644
--- a/jedi/evaluate/compiled/__init__.py
+++ b/jedi/evaluate/compiled/__init__.py
@@ -6,12 +6,13 @@ import re
 import sys
 import os
 from functools import partial
+from itertools import chain
 
 from jedi._compatibility import builtins as _builtins, unicode
 from jedi import debug
-from jedi.cache import underscore_memoization, memoize
+from jedi.cache import underscore_memoization, memoize_method
 from jedi.evaluate.sys_path import get_sys_path
-from jedi.parser.tree import Param, SubModule, Base, Operator
+from jedi.parser.tree import Param, Base
 from jedi.evaluate.helpers import FakeName
 from . import fake
 
@@ -137,11 +138,19 @@ class CompiledObject(Base):
         return self
 
     def get_defined_names(self):
+        return list(chain.from_iterable(self.names_dict.values()))
+
+        # TODO still used?
         if inspect.ismodule(self.obj):
             return self.instance_names()
         else:
             return type_names + self.instance_names()
 
+    @property
+    @underscore_memoization
+    def names_dict(self):
+        return LazyNamesDict(self._cls())
+
     def scope_names_generator(self, position=None, add_class_vars=True):
         yield self, self.get_defined_names()
 
@@ -237,6 +246,38 @@ class CompiledObject(Base):
         return []  # Builtins don't have imports
 
 
+class LazyNamesDict(object):
+    """
+    A names_dict instance for compiled objects, resembles the parser.tree.
+    """
+    def __init__(self, compiled_obj):
+        self._compiled_obj = compiled_obj
+
+    @memoize_method
+    def __getitem__(self, name):
+        try:
+            getattr(self._compiled_obj.obj, name)
+        except AttributeError:
+            raise KeyError('%s in %s not found.' % (name, self._compiled_obj))
+        return [CompiledName(self._compiled_obj, name)]
+
+    def values(self):
+        obj = self._compiled_obj.obj
+        names = dir(obj)
+
+        values = []
+        for name in names:
+            try:
+                values.append(self[name])
+            except KeyError:
+                # The dir function can be wrong.
+                pass
+
+        if not inspect.ismodule(obj):
+            values.append(type_names)
+        return values
+
+
 class CompiledName(FakeName):
     def __init__(self, obj, name):
         super(CompiledName, self).__init__(name)
@@ -250,6 +291,9 @@ class CompiledName(FakeName):
             name = None
         return '<%s: (%s).%s>' % (type(self).__name__, name, self.name)
 
+    def is_definition(self):
+        return True
+
     @property
     @underscore_memoization
     def parent(self):
@@ -408,14 +452,10 @@ def _parse_function_doc(doc):
     return param_str, ret
 
 
-class Builtin(CompiledObject, Base):
-    @memoize
+class Builtin(CompiledObject):
+    @memoize_method
     def get_by_name(self, name):
-        item = [n for n in self.get_defined_names() if n.get_code() == name][0]
-        return item.parent
-
-    def is_scope(self):
-        return True
+        return self.names_dict[name][0].parent
 
 
 def _a_generator(foo):
diff --git a/jedi/evaluate/finder.py b/jedi/evaluate/finder.py
index b4a75c6f..80510050 100644
--- a/jedi/evaluate/finder.py
+++ b/jedi/evaluate/finder.py
@@ -88,14 +88,18 @@ class NameFinder(object):
         # Only the names defined in the last position are valid definitions.
         last_names = []
         for name in reversed(sorted(names, key=lambda name: name.start_pos)):
+            if isinstance(name, compiled.CompiledName):
+                last_names.append(name)
+                continue
+
             if isinstance(self.name_str, pr.Name):
                 origin_scope = self.name_str.get_definition().parent
             else:
                 origin_scope = None
-            check = flow_analysis.break_check(self._evaluator,
-                                              scope,
-                                              name.get_definition(),
-                                              origin_scope)
+            stmt = name.get_definition()
+            if isinstance(stmt.parent, compiled.CompiledObject):
+                continue
+            check = flow_analysis.break_check(self._evaluator, scope, stmt, origin_scope)
             if check is not flow_analysis.UNREACHABLE:
                 last_names.append(name)
             if check is flow_analysis.REACHABLE:
@@ -166,8 +170,10 @@ class NameFinder(object):
                         or isinstance(name_list_scope, (pr.Lambda, er.Instance, InterpreterNamespace)) \
                         or isinstance(scope, compiled.CompiledObject):
                     # Always reachable.
+                    print('nons', scope)
                     names.append(name)
                 else:
+                    print('yess', scope)
                     check = flow_analysis.break_check(self._evaluator,
                                                       name_list_scope,
                                                       stmt,