diff --git a/_pytest/mark/structures.py b/_pytest/mark/structures.py
index 5550dc546..bfe9efc78 100644
--- a/_pytest/mark/structures.py
+++ b/_pytest/mark/structures.py
@@ -1,4 +1,4 @@
-from collections import namedtuple
+from collections import namedtuple, MutableMapping as MappingMixin
 import warnings
 from operator import attrgetter
 import inspect
@@ -328,3 +328,39 @@ class MarkGenerator(object):
 
 
 MARK_GEN = MarkGenerator()
+
+
+class NodeKeywords(MappingMixin):
+    def __init__(self, node):
+        self.node = node
+        self.parent = node.parent
+        self._markers = {node.name: True}
+
+    def __getitem__(self, key):
+        try:
+            return self._markers[key]
+        except KeyError:
+            if self.parent is None:
+                raise
+            return self.parent.keywords[key]
+
+    def __setitem__(self, key, value):
+        self._markers[key] = value
+
+    def __delitem__(self, key):
+        raise ValueError("cannot delete key in keywords dict")
+
+    def __iter__(self):
+        seen = set(self._markers)
+        if self.parent is not None:
+            seen.update(self.parent.keywords)
+        return iter(seen)
+
+    def __len__(self):
+        return len(self.__iter__())
+
+    def keys(self):
+        return list(self)
+
+    def __repr__(self):
+        return "<NodeKeywords for node %s>" % (self.node, )
\ No newline at end of file
diff --git a/_pytest/nodes.py b/_pytest/nodes.py
index e076d5747..9f51fc884 100644
--- a/_pytest/nodes.py
+++ b/_pytest/nodes.py
@@ -1,5 +1,4 @@
 from __future__ import absolute_import, division, print_function
-from collections import MutableMapping as MappingMixin
 import os
 
 import six
@@ -7,7 +6,7 @@ import py
 import attr
 
 import _pytest
-
+from _pytest.mark.structures import NodeKeywords
 
 SEP = "/"
 
@@ -66,42 +65,6 @@ class _CompatProperty(object):
         return getattr(__import__('pytest'), self.name)
 
 
-class NodeKeywords(MappingMixin):
-    def __init__(self, node):
-        self.node = node
-        self.parent = node.parent
-        self._markers = {node.name: True}
-
-    def __getitem__(self, key):
-        try:
-            return self._markers[key]
-        except KeyError:
-            if self.parent is None:
-                raise
-            return self.parent.keywords[key]
-
-    def __setitem__(self, key, value):
-        self._markers[key] = value
-
-    def __delitem__(self, key):
-        raise ValueError("cannot delete key in keywords dict")
-
-    def __iter__(self):
-        seen = set(self._markers)
-        if self.parent is not None:
-            seen.update(self.parent.keywords)
-        return iter(seen)
-
-    def __len__(self):
-        return len(self.__iter__())
-
-    def keys(self):
-        return list(self)
-
-    def __repr__(self):
-        return "<NodeKeywords for node %s>" % (self.node, )
-
-
 class Node(object):
     """ base class for Collector and Item the test collection tree.
     Collector subclasses have children, Items are terminal nodes."""