diff --git a/jedi/cache.py b/jedi/cache.py
index 77436f38..51a5807a 100644
--- a/jedi/cache.py
+++ b/jedi/cache.py
@@ -174,7 +174,7 @@ def save_module(path, name, parser, pickling=True):
 
 class _ModulePickling(object):
 
-    version = 5
+    version = 6
     """
     Version number (integer) for file system cache.
 
diff --git a/jedi/evaluate/builtin.py b/jedi/evaluate/builtin.py
index a0bc7e18..5270c5cd 100644
--- a/jedi/evaluate/builtin.py
+++ b/jedi/evaluate/builtin.py
@@ -165,8 +165,8 @@ class BuiltinModule(modules.CachedModule):
 
             if name == '__builtin__' and not is_py3k:
                 name = 'builtins'
-            path = os.path.dirname(os.path.abspath(__file__))
-            with open(os.path.sep.join([path, 'mixin', name]) + '.pym') as f:
+            path = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+            with open(os.path.join(path, 'mixin', name) + '.pym') as f:
                 s = f.read()
         except IOError:
             return {}