diff --git a/mozilla/content/base/src/nsDOMAttributeMap.cpp b/mozilla/content/base/src/nsDOMAttributeMap.cpp
index 3a05ad0d930..db632eacf17 100644
--- a/mozilla/content/base/src/nsDOMAttributeMap.cpp
+++ b/mozilla/content/base/src/nsDOMAttributeMap.cpp
@@ -481,7 +481,7 @@ nsDOMAttributeMap::RemoveNamedItemNS(const nsAString& aNamespaceURI,
   NS_ENSURE_SUCCESS(rv, rv);
 
   if (!*aReturn) {
-    return NS_OK;
+    return NS_ERROR_DOM_NOT_FOUND_ERR;
   }
 
   nsCOMPtr<nsIAttribute> attr = do_QueryInterface(*aReturn);
diff --git a/mozilla/dom/tests/mochitest/dom-level2-core/exclusions.js b/mozilla/dom/tests/mochitest/dom-level2-core/exclusions.js
index 8a0b61e1364..dd1269fa53a 100644
--- a/mozilla/dom/tests/mochitest/dom-level2-core/exclusions.js
+++ b/mozilla/dom/tests/mochitest/dom-level2-core/exclusions.js
@@ -59,16 +59,12 @@ bug371552 = ["elementhasattributens02"];
 wrongDocError = ["elementsetattributenodens05", "namednodemapsetnameditemns03",
                  "setAttributeNodeNS05", "setNamedItemNS02"];
 attrAppendChild = ["elementsetattributenodens06", "importNode01"];
-removeNamedItemNS = ["namednodemapremovenameditemns06",
-                     "namednodemapremovenameditemns07",
-                     "namednodemapremovenameditemns08",
-                     "removeNamedItemNS02"];
 bogusPrefix = ["nodesetprefix05", "nodesetprefix09", "prefix06", "prefix07"];
 prefixReplacement = ["setAttributeNodeNS04"];
 
 var todoTests = {};
 var exclusions = concat(dtdTests, bug371552, wrongDocError, attrAppendChild,
-                        removeNamedItemNS, bogusPrefix, prefixReplacement);
+                        bogusPrefix, prefixReplacement);
 for (var excludedTestName in exclusions) { 
   todoTests[exclusions[excludedTestName]] = true; 
 }