diff --git a/jedi/evaluate/__init__.py b/jedi/evaluate/__init__.py
index 94b5f2b0..1f1537e6 100644
--- a/jedi/evaluate/__init__.py
+++ b/jedi/evaluate/__init__.py
@@ -194,7 +194,7 @@ class Evaluator(object):
             if_stmt = if_stmt.parent
             if if_stmt.type in ('if_stmt', 'for_stmt'):
                 break
-            if if_stmt.is_scope():
+            if parser_utils.is_scope(if_stmt):
                 if_stmt = None
                 break
         predefined_if_name_dict = context.predefined_names.get(if_stmt)
@@ -537,7 +537,7 @@ class Evaluator(object):
             while True:
                 node = node.parent
 
-                if node.is_scope():
+                if parser_utils.is_scope(node):
                     return node
                 elif node.type in ('argument', 'testlist_comp'):
                     if node.children[1].type == 'comp_for':
@@ -553,7 +553,7 @@ class Evaluator(object):
                 return base_context
 
             is_funcdef = scope_node.type in ('funcdef', 'lambdef')
-            parent_scope = scope_node.get_parent_scope()
+            parent_scope = parser_utils.get_parent_scope(scope_node)
             parent_context = from_scope_node(parent_scope, child_is_funcdef=is_funcdef)
 
             if is_funcdef:
@@ -586,7 +586,7 @@ class Evaluator(object):
 
         base_node = base_context.tree_node
 
-        if node_is_context and node.is_scope():
+        if node_is_context and parser_utils.is_scope(node):
             scope_node = node
         else:
             if node.parent.type in ('funcdef', 'classdef'):
diff --git a/jedi/evaluate/dynamic.py b/jedi/evaluate/dynamic.py
index 6f294ff7..53977fd2 100644
--- a/jedi/evaluate/dynamic.py
+++ b/jedi/evaluate/dynamic.py
@@ -24,6 +24,7 @@ from jedi.evaluate.cache import memoize_default
 from jedi.evaluate import imports
 from jedi.evaluate.param import TreeArguments, create_default_param
 from jedi.common import to_list, unite
+from jedi.parser_utils import get_parent_scope
 
 
 MAX_PARAM_SEARCHES = 20
@@ -103,7 +104,7 @@ def _search_function_executions(evaluator, module_context, funcdef):
     func_string_name = funcdef.name.value
     compare_node = funcdef
     if func_string_name == '__init__':
-        cls = funcdef.get_parent_scope()
+        cls = get_parent_scope(funcdef)
         if isinstance(cls, tree.Class):
             func_string_name = cls.name.value
             compare_node = cls
diff --git a/jedi/evaluate/filters.py b/jedi/evaluate/filters.py
index 3b9950a2..198389a1 100644
--- a/jedi/evaluate/filters.py
+++ b/jedi/evaluate/filters.py
@@ -7,6 +7,7 @@ from abc import abstractmethod
 from jedi.parser.tree import search_ancestor
 from jedi.evaluate import flow_analysis
 from jedi.common import to_list, unite
+from jedi.parser_utils import get_parent_scope
 
 
 class AbstractNameDefinition(object):
@@ -189,7 +190,7 @@ class ParserTreeFilter(AbstractUsedNamesFilter):
         if parent.type == 'trailer':
             return False
         base_node = parent if parent.type in ('classdef', 'funcdef') else name
-        return base_node.get_parent_scope() == self._parser_scope
+        return get_parent_scope(base_node) == self._parser_scope
 
     def _check_flows(self, names):
         for name in sorted(names, key=lambda name: name.start_pos, reverse=True):
diff --git a/jedi/evaluate/finder.py b/jedi/evaluate/finder.py
index 74bc1ee8..1eb94c67 100644
--- a/jedi/evaluate/finder.py
+++ b/jedi/evaluate/finder.py
@@ -32,6 +32,7 @@ from jedi.evaluate import param
 from jedi.evaluate import helpers
 from jedi.evaluate.filters import get_global_filters
 from jedi.evaluate.context import ContextualizedName, ContextualizedNode
+from jedi.parser_utils import is_scope, get_parent_scope
 
 
 class NameFinder(object):
@@ -106,7 +107,7 @@ class NameFinder(object):
         if self._context.predefined_names:
             # TODO is this ok? node might not always be a tree.Name
             node = self._name
-            while node is not None and not node.is_scope():
+            while node is not None and not is_scope(node):
                 node = node.parent
                 if node.type in ("if_stmt", "for_stmt", "comp_for"):
                     try:
@@ -160,7 +161,7 @@ class NameFinder(object):
             if base_node.type == 'comp_for':
                 return types
             while True:
-                flow_scope = flow_scope.get_parent_scope(include_flows=True)
+                flow_scope = get_parent_scope(flow_scope, include_flows=True)
                 n = _check_flow_information(self._name_context, flow_scope,
                                             self._name, self._position)
                 if n is not None:
@@ -298,7 +299,7 @@ def _check_flow_information(context, flow, search_name, pos):
         return None
 
     result = None
-    if flow.is_scope():
+    if is_scope(flow):
         # Check for asserts.
         module_node = flow.get_root_node()
         try:
diff --git a/jedi/evaluate/flow_analysis.py b/jedi/evaluate/flow_analysis.py
index 06de185a..670b7a71 100644
--- a/jedi/evaluate/flow_analysis.py
+++ b/jedi/evaluate/flow_analysis.py
@@ -1,4 +1,6 @@
-from jedi.parser_utils import get_flow_branch_keyword
+from jedi.parser_utils import get_flow_branch_keyword, is_scope, get_parent_scope
+
+
 class Status(object):
     lookup_table = {}
 
@@ -32,14 +34,14 @@ UNSURE = Status(None, 'unsure')
 
 def _get_flow_scopes(node):
     while True:
-        node = node.get_parent_scope(include_flows=True)
-        if node is None or node.is_scope():
+        node = get_parent_scope(node, include_flows=True)
+        if node is None or is_scope(node):
             return
         yield node
 
 
 def reachability_check(context, context_scope, node, origin_scope=None):
-    first_flow_scope = node.get_parent_scope(include_flows=True)
+    first_flow_scope = get_parent_scope(node, include_flows=True)
     if origin_scope is not None:
         origin_flow_scopes = list(_get_flow_scopes(origin_scope))
         node_flow_scopes = list(_get_flow_scopes(node))
@@ -95,7 +97,7 @@ def _break_check(context, context_scope, flow_scope, node):
         return reachable
 
     if context_scope != flow_scope and context_scope != flow_scope.parent:
-        flow_scope = flow_scope.get_parent_scope(include_flows=True)
+        flow_scope = get_parent_scope(flow_scope, include_flows=True)
         return reachable & _break_check(context, context_scope, flow_scope, node)
     else:
         return reachable
diff --git a/jedi/evaluate/helpers.py b/jedi/evaluate/helpers.py
index 12739bbc..d85e94f8 100644
--- a/jedi/evaluate/helpers.py
+++ b/jedi/evaluate/helpers.py
@@ -3,6 +3,7 @@ from itertools import chain
 from contextlib import contextmanager
 
 from jedi.parser.python import tree
+from jedi.parser_utils import get_parent_scope
 
 
 def deep_ast_copy(obj):
@@ -143,7 +144,7 @@ def get_module_names(module, all_scopes):
         # parent_scope. There's None as a parent, because nodes in the module
         # node have the parent module and not suite as all the others.
         # Therefore it's important to catch that case.
-        names = [n for n in names if n.get_parent_scope().parent in (module, None)]
+        names = [n for n in names if get_parent_scope(n).parent in (module, None)]
     return names
 
 
diff --git a/jedi/evaluate/instance.py b/jedi/evaluate/instance.py
index d0cd812a..9b131f84 100644
--- a/jedi/evaluate/instance.py
+++ b/jedi/evaluate/instance.py
@@ -11,6 +11,7 @@ from jedi.cache import memoize_method
 from jedi.evaluate import representation as er
 from jedi.evaluate.dynamic import search_params
 from jedi.evaluate import iterable
+from jedi.parser_utils import get_parent_scope
 
 
 class AbstractInstanceContext(Context):
@@ -151,7 +152,7 @@ class AbstractInstanceContext(Context):
     def create_instance_context(self, class_context, node):
         if node.parent.type in ('funcdef', 'classdef'):
             node = node.parent
-        scope = node.get_parent_scope()
+        scope = get_parent_scope(node)
         if scope == class_context.tree_node:
             return class_context
         else:
@@ -189,7 +190,7 @@ class CompiledInstance(AbstractInstanceContext):
         return compiled.CompiledContextName(self, self.class_context.name.string_name)
 
     def create_instance_context(self, class_context, node):
-        if node.get_parent_scope().type == 'classdef':
+        if get_parent_scope(node).type == 'classdef':
             return class_context
         else:
             return super(CompiledInstance, self).create_instance_context(class_context, node)
@@ -332,7 +333,7 @@ class InstanceClassFilter(filters.ParserTreeFilter):
         while node is not None:
             if node == self._parser_scope or node == self.context:
                 return True
-            node = node.get_parent_scope()
+            node = get_parent_scope(node)
         return False
 
     def _access_possible(self, name):
diff --git a/jedi/evaluate/representation.py b/jedi/evaluate/representation.py
index 9e7ab312..fb505780 100644
--- a/jedi/evaluate/representation.py
+++ b/jedi/evaluate/representation.py
@@ -276,7 +276,7 @@ class FunctionContext(use_metaclass(CachedMetaClass, context.TreeContext)):
     def py__class__(self):
         # This differentiation is only necessary for Python2. Python3 does not
         # use a different method class.
-        if isinstance(self.tree_node.get_parent_scope(), tree.Class):
+        if isinstance(parser_utils.get_parent_scope(self.tree_node), tree.Class):
             name = 'METHOD_CLASS'
         else:
             name = 'FUNCTION_CLASS'
diff --git a/jedi/parser/python/tree.py b/jedi/parser/python/tree.py
index f8924d28..a07ace95 100644
--- a/jedi/parser/python/tree.py
+++ b/jedi/parser/python/tree.py
@@ -59,19 +59,6 @@ class DocstringMixin(object):
 
 
 class PythonMixin(object):
-    def get_parent_scope(self, include_flows=False):
-        """
-        Returns the underlying scope.
-        """
-        scope = self.parent
-        while scope is not None:
-            if include_flows and isinstance(scope, Flow):
-                return scope
-            if scope.is_scope():
-                break
-            scope = scope.parent
-        return scope
-
     def get_definition(self):
         if self.type in ('newline', 'endmarker'):
             raise ValueError('Cannot get the indentation of whitespace or indentation.')
@@ -90,10 +77,6 @@ class PythonMixin(object):
                 break
         return scope
 
-    def is_scope(self):
-        # Default is not being a scope. Just inherit from Scope.
-        return False
-
     def get_name_of_position(self, position):
         for c in self.children:
             if isinstance(c, Leaf):
@@ -267,9 +250,6 @@ class Scope(PythonBaseNode, DocstringMixin):
 
         return scan(self.children)
 
-    def is_scope(self):
-        return True
-
     def get_suite(self):
         """
         Returns the part that is executed by the function.
@@ -1057,9 +1037,6 @@ class CompFor(PythonBaseNode):
     type = 'comp_for'
     __slots__ = ()
 
-    def is_scope(self):
-        return True
-
     def get_defined_names(self):
         """
         Returns the a list of `Name` that the comprehension defines.
diff --git a/jedi/parser_utils.py b/jedi/parser_utils.py
index 47a9a17c..df340f6b 100644
--- a/jedi/parser_utils.py
+++ b/jedi/parser_utils.py
@@ -217,3 +217,21 @@ def get_following_comment_same_line(node):
         comment = comment[:comment.index("\n")]
     return comment
 
+
+def is_scope(node):
+    return node.type in ('file_input', 'classdef', 'funcdef', 'lambdef', 'comp_for')
+
+
+def get_parent_scope(node, include_flows=False):
+    """
+    Returns the underlying scope.
+    """
+    scope = node.parent
+    while scope is not None:
+        if include_flows and isinstance(scope, tree.Flow):
+            return scope
+        if is_scope(scope):
+            break
+        scope = scope.parent
+    return scope
+