diff --git a/jedi/evaluate/compiled/fake/builtins.pym b/jedi/evaluate/compiled/fake/builtins.pym
index 692c8f8b..2fc50ce1 100644
--- a/jedi/evaluate/compiled/fake/builtins.pym
+++ b/jedi/evaluate/compiled/fake/builtins.pym
@@ -6,6 +6,17 @@ possible for the auto completion.
 """
 
 
+def next(iterator, default=None):
+    if random.choice([0, 1]):
+        if hasattr("next"):
+            return iterator.next()
+        else:
+            return iterator.__next__()
+    else:
+        if default is not None:
+            return default
+
+
 def iter(collection, sentinel=None):
     if sentinel:
         yield collection()
diff --git a/jedi/evaluate/instance.py b/jedi/evaluate/instance.py
index 5190c63f..ee4753a9 100644
--- a/jedi/evaluate/instance.py
+++ b/jedi/evaluate/instance.py
@@ -213,14 +213,18 @@ class CompiledInstanceName(compiled.CompiledName):
         self._instance = instance
 
     def infer(self):
-        for v in super(CompiledInstanceName, self).infer():
-            if isinstance(v, er.FunctionContext):
+        for result_context in super(CompiledInstanceName, self).infer():
+            if isinstance(result_context, er.FunctionContext):
+                parent_context = result_context.parent_context
+                while parent_context.is_class():
+                    parent_context = parent_context.parent_context
+
                 yield BoundMethod(
-                    v.evaluator, self._instance, self.parent_context,
-                    v.parent_context, v.funcdef
+                    result_context.evaluator, self._instance, self.parent_context,
+                    parent_context, result_context.funcdef
                 )
             else:
-                yield v
+                yield result_context
 
 
 class CompiledInstanceClassFilter(compiled.CompiledObjectFilter):
@@ -282,7 +286,7 @@ class LazyInstanceClassName(LazyInstanceName):
                 # functions. Only other functions and modules will resolve
                 # those things.
                 parent_context = result_context.parent_context
-                while isinstance(parent_context, er.ClassContext):
+                while parent_context.is_class():
                     parent_context = parent_context.parent_context
 
                 yield BoundMethod(
diff --git a/jedi/evaluate/iterable.py b/jedi/evaluate/iterable.py
index 568dd4e1..6fb52d06 100644
--- a/jedi/evaluate/iterable.py
+++ b/jedi/evaluate/iterable.py
@@ -123,7 +123,7 @@ 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):
+        if python_version_match and python_version_match != 2 + int(is_py3):
             # Some functions do only apply to certain versions.
             return func
         dct = func.__dict__.setdefault('registered_builtin_methods', {})
diff --git a/jedi/evaluate/stdlib.py b/jedi/evaluate/stdlib.py
index eb220fa4..cfe8dee9 100644
--- a/jedi/evaluate/stdlib.py
+++ b/jedi/evaluate/stdlib.py
@@ -17,7 +17,7 @@ from jedi.common import unite
 from jedi.evaluate import compiled
 from jedi.evaluate import representation as er
 from jedi.evaluate.instance import InstanceFunctionExecution, \
-    AbstractInstanceContext, CompiledInstance
+    AbstractInstanceContext, CompiledInstance, BoundMethod
 from jedi.evaluate import iterable
 from jedi.parser import ParserWithRecovery
 from jedi import debug
@@ -31,6 +31,9 @@ class NotInStdLib(LookupError):
 
 
 def execute(evaluator, obj, arguments):
+    if isinstance(obj, BoundMethod):
+        raise NotInStdLib()
+
     try:
         obj_name = obj.name.string_name
     except AttributeError:
@@ -108,6 +111,10 @@ def argument_clinic(string, want_obj=False, want_context=False, want_arguments=F
 
 @argument_clinic('iterator[, default], /')
 def builtins_next(evaluator, iterators, defaults):
+    """
+    TODO this function is currently not used. It's a stab at implementing next
+    in a different way than fake objects. This would be a bit more flexible.
+    """
     if evaluator.python_version[0] == 2:
         name = 'next'
     else:
@@ -268,7 +275,6 @@ def _return_first_param(evaluator, firsts):
 
 _implemented = {
     'builtins': {
-        'next': builtins_next,
         'getattr': builtins_getattr,
         'type': builtins_type,
         'super': builtins_super,