--- a/dom/html/HTMLAllCollection.cpp
+++ b/dom/html/HTMLAllCollection.cpp
@@ -186,17 +186,21 @@ HTMLAllCollection::NamedGetter(const nsA
     return;
   }
 
   // Check if there are more than 1 entries. Do this by getting the second one
   // rather than the length since getting the length always requires walking
   // the entire document.
   if (docAllList->Item(1, true)) {
     aFound = true;
-    aResult.SetValue().SetAsHTMLCollection() = docAllList;
+    // We need to return a different value for each call per spec
+    nsCOMPtr<nsIAtom> id = NS_Atomize(aID);
+    aResult.SetValue().SetAsHTMLCollection() =
+      new nsContentList(mDocument, DocAllResultMatch, nullptr, nullptr, true,
+                        id);
     return;
   }
 
   // There's only 0 or 1 items. Return the first one or null.
   if (nsIContent* node = docAllList->Item(0, true)) {
     aFound = true;
     aResult.SetValue().SetAsElement() = node->AsElement();
     return;

deleted file mode 100644
--- a/testing/web-platform/meta/html/infrastructure/common-dom-interfaces/collections/htmlallcollection.html.ini
+++ /dev/null
@@ -1,5 +0,0 @@
-[htmlallcollection.html]
-  type: testharness
-  [collections are new live HTMLCollection instances]
-    expected: FAIL
-