diff --git a/jedi/evaluate/context/iterable.py b/jedi/evaluate/context/iterable.py
index ccdf5db3..3f85ad80 100644
--- a/jedi/evaluate/context/iterable.py
+++ b/jedi/evaluate/context/iterable.py
@@ -448,6 +448,8 @@ class FakeDict(_FakeArray):
             yield LazyKnownContext(compiled.create_simple_object(self.evaluator, key))
 
     def py__getitem__(self, index):
+        if isinstance(index, bytes):
+            index = force_unicode(index)
         return self._dct[index].infer()
 
     def dict_values(self):
diff --git a/jedi/evaluate/filters.py b/jedi/evaluate/filters.py
index f7007b71..c9e95998 100644
--- a/jedi/evaluate/filters.py
+++ b/jedi/evaluate/filters.py
@@ -269,8 +269,8 @@ class DictFilter(AbstractFilter):
             value = self._convert(name, self._dct[name])
         except KeyError:
             return []
-
-        return list(self._filter([value]))
+        else:
+            return list(self._filter([value]))
 
     def values(self):
         return self._filter(self._convert(*item) for item in self._dct.items())
@@ -306,7 +306,12 @@ class SpecialMethodFilter(DictFilter):
     class SpecialMethodName(AbstractNameDefinition):
         api_type = u'function'
 
-        def __init__(self, parent_context, string_name, callable_, builtin_context):
+        def __init__(self, parent_context, string_name, value, builtin_context):
+            callable_, python_version = value
+            if python_version is not None and \
+                    python_version != parent_context.evaluator.environment.version_info.major:
+                raise KeyError
+
             self.parent_context = parent_context
             self.string_name = string_name
             self._callable = callable_
@@ -355,14 +360,11 @@ def has_builtin_methods(cls):
 
 
 def register_builtin_method(method_name, python_version_match=None):
-    def wrapper(func):
-        if python_version_match and python_version_match != 2 + int(is_py3):
-            # Some functions do only apply to certain versions.
-            return func
+    def decorator(func):
         dct = func.__dict__.setdefault('registered_builtin_methods', {})
-        dct[method_name] = func
+        dct[method_name] = func, python_version_match
         return func
-    return wrapper
+    return decorator
 
 
 def get_global_filters(evaluator, context, until_position, origin_scope):
diff --git a/jedi/evaluate/sys_path.py b/jedi/evaluate/sys_path.py
index 11728430..e34908fe 100644
--- a/jedi/evaluate/sys_path.py
+++ b/jedi/evaluate/sys_path.py
@@ -1,7 +1,7 @@
 import os
 import imp
 
-from jedi._compatibility import unicode
+from jedi._compatibility import unicode, force_unicode
 from jedi.evaluate.cache import evaluator_method_cache
 from jedi.evaluate.base_context import ContextualizedNode
 from jedi.evaluate.helpers import is_string
@@ -11,16 +11,17 @@ from jedi.evaluate.utils import ignored
 
 
 def _abs_path(module_context, path):
-    module_path = module_context.py__file__()
     if os.path.isabs(path):
         return path
 
+    module_path = module_context.py__file__()
     if module_path is None:
         # In this case we have no idea where we actually are in the file
         # system.
         return None
 
     base_dir = os.path.dirname(module_path)
+    path = force_unicode(path)
     return os.path.abspath(os.path.join(base_dir, path))