diff --git a/dom/base/Document.cpp b/dom/base/Document.cpp
index 5d52dbd91c72..b761ab192ae0 100644
--- a/dom/base/Document.cpp
+++ b/dom/base/Document.cpp
@@ -91,6 +91,7 @@
 #include "mozilla/dom/FeaturePolicy.h"
 #include "mozilla/dom/FeaturePolicyUtils.h"
 #include "mozilla/dom/FramingChecker.h"
+#include "mozilla/dom/HTMLAllCollection.h"
 #include "mozilla/dom/HTMLSharedElement.h"
 #include "mozilla/dom/Navigator.h"
 #include "mozilla/dom/Performance.h"
@@ -2004,6 +2005,7 @@ NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INTERNAL(Document)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mSuppressedEventListener)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPrototypeDocument)
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mMidasCommandManager)
+  NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mAll)
 
   // Traverse all our nsCOMArrays.
   NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mPreloadingImages)
@@ -5632,6 +5634,13 @@ void Document::CaptureEvents() { WarnOnceAbout(Document::eUseOfCaptureEvents); }
 
 void Document::ReleaseEvents() { WarnOnceAbout(Document::eUseOfReleaseEvents); }
 
+HTMLAllCollection* Document::All() {
+  if (!mAll) {
+    mAll = new HTMLAllCollection(this);
+  }
+  return mAll;
+}
+
 nsresult Document::GetSrcdocData(nsAString& aSrcdocData) {
   if (mIsSrcdocDocument) {
     nsCOMPtr<nsIInputStreamChannel> inStrmChan = do_QueryInterface(mChannel);
diff --git a/dom/base/Document.h b/dom/base/Document.h
index b657e80400b8..a5ad5781f158 100644
--- a/dom/base/Document.h
+++ b/dom/base/Document.h
@@ -185,6 +185,7 @@ class FeaturePolicy;
 class FontFaceSet;
 class FrameRequestCallback;
 class ImageTracker;
+class HTMLAllCollection;
 class HTMLBodyElement;
 class HTMLSharedElement;
 class HTMLImageElement;
@@ -3582,6 +3583,8 @@ class Document : public nsINode,
   void CaptureEvents();
   void ReleaseEvents();
 
+  mozilla::dom::HTMLAllCollection* All();
+
   static bool IsUnprefixedFullscreenEnabled(JSContext* aCx, JSObject* aObject);
   static bool DocumentSupportsL10n(JSContext* aCx, JSObject* aObject);
   static bool IsWebAnimationsEnabled(JSContext* aCx, JSObject* aObject);
@@ -5215,6 +5218,8 @@ class Document : public nsINode,
   RefPtr<XULBroadcastManager> mXULBroadcastManager;
   RefPtr<XULPersist> mXULPersist;
 
+  RefPtr<mozilla::dom::HTMLAllCollection> mAll;
+
   // document lightweight theme for use with :-moz-lwtheme,
   // :-moz-lwtheme-brighttext and :-moz-lwtheme-darktext
   DocumentTheme mDocLWTheme;
diff --git a/dom/html/HTMLAllCollection.cpp b/dom/html/HTMLAllCollection.cpp
index 675898020d06..413d25a41998 100644
--- a/dom/html/HTMLAllCollection.cpp
+++ b/dom/html/HTMLAllCollection.cpp
@@ -8,13 +8,15 @@
 
 #include "mozilla/dom/HTMLAllCollectionBinding.h"
 #include "mozilla/dom/Nullable.h"
+#include "mozilla/dom/Document.h"
 #include "mozilla/dom/Element.h"
-#include "nsHTMLDocument.h"
+#include "nsContentList.h"
+#include "nsGenericHTMLElement.h"
 
 namespace mozilla {
 namespace dom {
 
-HTMLAllCollection::HTMLAllCollection(nsHTMLDocument* aDocument)
+HTMLAllCollection::HTMLAllCollection(mozilla::dom::Document* aDocument)
     : mDocument(aDocument) {
   MOZ_ASSERT(mDocument);
 }
diff --git a/dom/html/HTMLAllCollection.h b/dom/html/HTMLAllCollection.h
index e999cfc30db4..b8b4269b5bd1 100644
--- a/dom/html/HTMLAllCollection.h
+++ b/dom/html/HTMLAllCollection.h
@@ -15,12 +15,12 @@
 #include <stdint.h>
 
 class nsContentList;
-class nsHTMLDocument;
 class nsINode;
 
 namespace mozilla {
 namespace dom {
 
+class Document;
 class Element;
 class OwningHTMLCollectionOrElement;
 template <typename>
@@ -32,7 +32,7 @@ class HTMLAllCollection final : public nsISupports, public nsWrapperCache {
   ~HTMLAllCollection();
 
  public:
-  explicit HTMLAllCollection(nsHTMLDocument* aDocument);
+  explicit HTMLAllCollection(mozilla::dom::Document* aDocument);
 
   NS_DECL_CYCLE_COLLECTING_ISUPPORTS
   NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS(HTMLAllCollection)
@@ -80,7 +80,7 @@ class HTMLAllCollection final : public nsISupports, public nsWrapperCache {
    */
   Element* Item(uint32_t aIndex);
 
-  RefPtr<nsHTMLDocument> mDocument;
+  RefPtr<mozilla::dom::Document> mDocument;
   RefPtr<nsContentList> mCollection;
   nsRefPtrHashtable<nsStringHashKey, nsContentList> mNamedMap;
 };
diff --git a/dom/html/nsHTMLDocument.cpp b/dom/html/nsHTMLDocument.cpp
index ca39d3ceb131..bec9899817b6 100644
--- a/dom/html/nsHTMLDocument.cpp
+++ b/dom/html/nsHTMLDocument.cpp
@@ -9,7 +9,6 @@
 #include "nsIContentPolicy.h"
 #include "mozilla/DebugOnly.h"
 #include "mozilla/PresShell.h"
-#include "mozilla/dom/HTMLAllCollection.h"
 #include "nsCommandManager.h"
 #include "nsCOMPtr.h"
 #include "nsGlobalWindow.h"
@@ -158,10 +157,6 @@ nsHTMLDocument::nsHTMLDocument()
 
 nsHTMLDocument::~nsHTMLDocument() {}
 
-NS_IMPL_CYCLE_COLLECTION_INHERITED(nsHTMLDocument, Document, mAll)
-
-NS_IMPL_ISUPPORTS_CYCLE_COLLECTION_INHERITED_0(nsHTMLDocument, Document)
-
 JSObject* nsHTMLDocument::WrapNode(JSContext* aCx,
                                    JS::Handle<JSObject*> aGivenProto) {
   return HTMLDocument_Binding::Wrap(aCx, this, aGivenProto);
@@ -780,13 +775,6 @@ bool nsHTMLDocument::MatchFormControls(Element* aElement, int32_t aNamespaceID,
   return aElement->IsNodeOfType(nsIContent::eHTML_FORM_CONTROL);
 }
 
-HTMLAllCollection* nsHTMLDocument::All() {
-  if (!mAll) {
-    mAll = new HTMLAllCollection(this);
-  }
-  return mAll;
-}
-
 nsresult nsHTMLDocument::Clone(dom::NodeInfo* aNodeInfo,
                                nsINode** aResult) const {
   NS_ASSERTION(aNodeInfo->NodeInfoManager() == mNodeInfoManager,
diff --git a/dom/html/nsHTMLDocument.h b/dom/html/nsHTMLDocument.h
index fc05cad6523c..831bd71a5d90 100644
--- a/dom/html/nsHTMLDocument.h
+++ b/dom/html/nsHTMLDocument.h
@@ -27,7 +27,6 @@ class nsILoadGroup;
 
 namespace mozilla {
 namespace dom {
-class HTMLAllCollection;
 template <typename T>
 struct Nullable;
 class WindowProxyHolder;
@@ -49,9 +48,6 @@ class nsHTMLDocument : public mozilla::dom::Document {
   nsHTMLDocument();
   virtual nsresult Init() override;
 
-  NS_DECL_ISUPPORTS_INHERITED
-  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsHTMLDocument, Document)
-
   // Document
   virtual void Reset(nsIChannel* aChannel, nsILoadGroup* aLoadGroup) override;
   virtual void ResetToURI(nsIURI* aURI, nsILoadGroup* aLoadGroup,
@@ -73,8 +69,6 @@ class nsHTMLDocument : public mozilla::dom::Document {
 
   nsContentList* GetExistingForms() const { return mForms; }
 
-  mozilla::dom::HTMLAllCollection* All();
-
   // Returns whether an object was found for aName.
   bool ResolveName(JSContext* aCx, const nsAString& aName,
                    JS::MutableHandle<JS::Value> aRetval,
@@ -172,8 +166,6 @@ class nsHTMLDocument : public mozilla::dom::Document {
   friend class ContentListHolder;
   ContentListHolder* mContentListHolder;
 
-  RefPtr<mozilla::dom::HTMLAllCollection> mAll;
-
   /** # of forms in the document, synchronously set */
   int32_t mNumForms;
 
diff --git a/dom/webidl/Document.webidl b/dom/webidl/Document.webidl
index 006a2990ce97..4a4c55810da5 100644
--- a/dom/webidl/Document.webidl
+++ b/dom/webidl/Document.webidl
@@ -276,7 +276,7 @@ partial interface Document {
   void captureEvents();
   void releaseEvents();
 
-  //(HTML only)[SameObject] readonly attribute HTMLAllCollection all;
+  [SameObject] readonly attribute HTMLAllCollection all;
 };
 
 // https://fullscreen.spec.whatwg.org/#api
diff --git a/dom/webidl/HTMLDocument.webidl b/dom/webidl/HTMLDocument.webidl
index ddc2e2d3c627..5b26fe71fb52 100644
--- a/dom/webidl/HTMLDocument.webidl
+++ b/dom/webidl/HTMLDocument.webidl
@@ -9,8 +9,6 @@ interface HTMLDocument : Document {
   // DOM tree accessors
   [Throws]
   getter object (DOMString name);
-
-  readonly attribute HTMLAllCollection all;
 };
 
 partial interface HTMLDocument {
diff --git a/testing/web-platform/meta/html/dom/interfaces.https.html.ini b/testing/web-platform/meta/html/dom/interfaces.https.html.ini
index 84c68fe7331c..a4af994a7cc6 100644
--- a/testing/web-platform/meta/html/dom/interfaces.https.html.ini
+++ b/testing/web-platform/meta/html/dom/interfaces.https.html.ini
@@ -1,8 +1,5 @@
 prefs: [dom.security.featurePolicy.enabled:true]
 [interfaces.https.html?include=(Document|Window)]
-  [Document interface: attribute all]
-    expected: FAIL
-
   [Document interface: attribute oncancel]
     expected: FAIL
 
@@ -30,9 +27,6 @@ prefs: [dom.security.featurePolicy.enabled:true]
   [Document interface: new Document() must inherit property "onsecuritypolicyviolation" with the proper type]
     expected: FAIL
 
-  [Document interface: document.implementation.createDocument(null, "", null) must inherit property "all" with the proper type]
-    expected: FAIL
-
   [Document interface: document.implementation.createDocument(null, "", null) must inherit property "oncancel" with the proper type]
     expected: FAIL
 
diff --git a/testing/web-platform/tests/xhr/responsexml-document-properties.htm b/testing/web-platform/tests/xhr/responsexml-document-properties.htm
index 9071fab121fc..c27a4482cd20 100644
--- a/testing/web-platform/tests/xhr/responsexml-document-properties.htm
+++ b/testing/web-platform/tests/xhr/responsexml-document-properties.htm
@@ -28,7 +28,7 @@
         defaultView:null,
         body:null,
         doctype:null,
-        all:undefined,
+        all:HTMLAllCollection,
         cookie:''
       }
 
@@ -38,7 +38,11 @@
 
       function runTest(name, value){
         test(function(){
-          assert_equals(client.responseXML[name], value)
+          if (name == "all") {
+            assert_equals(client.responseXML[name].__proto__, value.prototype)
+          } else {
+            assert_equals(client.responseXML[name], value)
+          }
         }, name)
       }