diff --git a/Lib/xml/dom/__init__.py b/Lib/xml/dom/__init__.py
index 4401bdf..97cf9a6 100644
--- a/Lib/xml/dom/__init__.py
+++ b/Lib/xml/dom/__init__.py
@@ -17,6 +17,7 @@
 
 class Node:
     """Class giving the NodeType constants."""
+    __slots__ = ()
 
     # DOM implementations may use this as a base class for their own
     # Node implementations.  If they don't, the constants defined here
diff --git a/Lib/xml/dom/minidom.py b/Lib/xml/dom/minidom.py
index 3de8a4d..275e20c 100644
--- a/Lib/xml/dom/minidom.py
+++ b/Lib/xml/dom/minidom.py
@@ -62,10 +62,7 @@
             return writer.stream.getvalue()
 
     def hasChildNodes(self):
-        if self.childNodes:
-            return True
-        else:
-            return False
+        return bool(self.childNodes)
 
     def _get_childNodes(self):
         return self.childNodes
@@ -930,6 +927,7 @@
     """Mixin that makes childless-ness easy to implement and avoids
     the complexity of the Node methods that deal with children.
     """
+    __slots__ = ()
 
     attributes = None
     childNodes = EmptyNodeList()
@@ -1067,6 +1065,8 @@
 
 
 class Text(CharacterData):
+    __slots__ = ()
+
     nodeType = Node.TEXT_NODE
     nodeName = "#text"
     attributes = None
@@ -1188,6 +1188,8 @@
 
 
 class CDATASection(Text):
+    __slots__ = ()
+
     nodeType = Node.CDATA_SECTION_NODE
     nodeName = "#cdata-section"
 
@@ -1266,8 +1268,7 @@
 class Identified:
     """Mix-in class that supports the publicId and systemId attributes."""
 
-    # XXX this does not work, this is an old-style class
-    # __slots__ = 'publicId', 'systemId'
+    __slots__ = 'publicId', 'systemId'
 
     def _identified_mixin_init(self, publicId, systemId):
         self.publicId = publicId