diff --git a/Lib/test/test_minidom.py b/Lib/test/test_minidom.py
index 457480349a4..5cc1e692938 100644
--- a/Lib/test/test_minidom.py
+++ b/Lib/test/test_minidom.py
@@ -98,6 +98,17 @@ def testLegalChildren():
     else:
         print "dom.appendChild didn't raise HierarchyRequestErr"
 
+    nodemap = elem.attributes 
+    try: nodemap.setNamedItem(text)
+    except HierarchyRequestErr: pass
+    else:
+        print "NamedNodeMap.setNamedItem didn't raise HierarchyRequestErr"
+
+    try: nodemap.setNamedItemNS(text)
+    except HierarchyRequestErr: pass
+    else:
+        print "NamedNodeMap.setNamedItemNS didn't raise HierarchyRequestErr"
+
     elem.appendChild(text)
     dom.unlink()
 
diff --git a/Lib/xml/dom/minidom.py b/Lib/xml/dom/minidom.py
index ef1a2bff229..b4ae267511f 100644
--- a/Lib/xml/dom/minidom.py
+++ b/Lib/xml/dom/minidom.py
@@ -378,6 +378,9 @@ class NamedNodeMap:
         self.setNamedItem(node)
 
     def setNamedItem(self, node):
+        if not isinstance(node, Attr):
+            raise HierarchyRequestErr, \
+                  "%s cannot be child of %s" % (repr(node), repr(self))
         old = self._attrs.get(node.name)
         if old:
             old.unlink()