diff --git a/jedi/evaluate/filters.py b/jedi/evaluate/filters.py
index 231b8825..0784c675 100644
--- a/jedi/evaluate/filters.py
+++ b/jedi/evaluate/filters.py
@@ -4,7 +4,7 @@ are needed for name resolution.
 """
 from abc import abstractmethod
 
-from jedi.parser.python.tree import search_ancestor
+from jedi.parser.tree import search_ancestor
 from jedi.evaluate import flow_analysis
 from jedi.common import to_list, unite
 
diff --git a/jedi/evaluate/finder.py b/jedi/evaluate/finder.py
index b5b46e6e..74bc1ee8 100644
--- a/jedi/evaluate/finder.py
+++ b/jedi/evaluate/finder.py
@@ -16,6 +16,7 @@ check for -> a is a string). There's big potential in these checks.
 """
 
 from jedi.parser.python import tree
+from jedi.parser.tree import search_ancestor
 from jedi import debug
 from jedi.common import unite
 from jedi import settings
@@ -310,7 +311,7 @@ def _check_flow_information(context, flow, search_name, pos):
         ])
 
         for name in names:
-            ass = tree.search_ancestor(name, 'assert_stmt')
+            ass = search_ancestor(name, 'assert_stmt')
             if ass is not None:
                 result = _check_isinstance_type(context, ass.assertion, search_name)
                 if result is not None:
diff --git a/jedi/evaluate/imports.py b/jedi/evaluate/imports.py
index 20890c95..fc1fcd8b 100644
--- a/jedi/evaluate/imports.py
+++ b/jedi/evaluate/imports.py
@@ -22,6 +22,7 @@ from jedi import settings
 from jedi.common import source_to_unicode, unite
 from jedi.parser.python import parse
 from jedi.parser.python import tree
+from jedi.parser.tree import search_ancestor
 from jedi.parser.cache import parser_cache
 from jedi.evaluate import sys_path
 from jedi.evaluate import helpers
@@ -36,7 +37,7 @@ from jedi.evaluate.filters import AbstractNameDefinition
 @memoize_default(default=set())
 def infer_import(context, tree_name, is_goto=False):
     module_context = context.get_root_context()
-    import_node = tree.search_ancestor(tree_name, ('import_name', 'import_from'))
+    import_node = search_ancestor(tree_name, ('import_name', 'import_from'))
     import_path = import_node.path_for_name(tree_name)
     from_import_name = None
     evaluator = context.evaluator
diff --git a/jedi/parser/python/__init__.py b/jedi/parser/python/__init__.py
index c435e65e..f4ef81de 100644
--- a/jedi/parser/python/__init__.py
+++ b/jedi/parser/python/__init__.py
@@ -58,7 +58,8 @@ def parse(code=None, path=None, grammar=None, error_recovery=True,
 
     :param code: A unicode string that contains Python code.
     :param path: The path to the file you want to open. Only needed for caching.
-    :param grammar: A Python grammar file, created with load_grammar.
+    :param grammar: A Python grammar file, created with load_grammar. You may
+        not specify it. In that case it's the current Python version.
     :param error_recovery: If enabled, any code will be returned. If it is
         invalid, it will be returned as an error node. If disabled, you will
         get a ParseError when encountering syntax errors in your code.
diff --git a/jedi/parser/python/tree.py b/jedi/parser/python/tree.py
index 4e8c2804..ebff95eb 100644
--- a/jedi/parser/python/tree.py
+++ b/jedi/parser/python/tree.py
@@ -30,17 +30,8 @@ See also :attr:`Scope.subscopes` and :attr:`Scope.statements`.
 from itertools import chain
 
 from jedi._compatibility import utf8_repr, unicode
-from jedi.parser.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf
-
-
-def search_ancestor(node, node_type_or_types):
-    if not isinstance(node_type_or_types, (list, tuple)):
-        node_type_or_types = (node_type_or_types,)
-
-    while True:
-        node = node.parent
-        if node is None or node.type in node_type_or_types:
-            return node
+from jedi.parser.tree import Node, BaseNode, Leaf, ErrorNode, ErrorLeaf, \
+    search_ancestor
 
 
 class DocstringMixin(object):
diff --git a/jedi/parser/tree.py b/jedi/parser/tree.py
index db9eaef5..05de527b 100644
--- a/jedi/parser/tree.py
+++ b/jedi/parser/tree.py
@@ -2,6 +2,16 @@ from abc import abstractmethod, abstractproperty
 from jedi._compatibility import utf8_repr, encoding, is_py3
 
 
+def search_ancestor(node, node_type_or_types):
+    if not isinstance(node_type_or_types, (list, tuple)):
+        node_type_or_types = (node_type_or_types,)
+
+    while True:
+        node = node.parent
+        if node is None or node.type in node_type_or_types:
+            return node
+
+
 class NodeOrLeaf(object):
     """
     The base class for nodes and leaves.