diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index 30918f2eb..9891070aa 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -2862,6 +2862,7 @@ interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEven
     createElement(tagName: "x-ms-webview"): MSHTMLWebViewElement;
     createElement(tagName: "xmp"): HTMLPreElement;
     createElement(tagName: string): HTMLElement;
+    createElementNS(namespaceURI: "http://www.w3.org/1999/xhtml", qualifiedName: string): HTMLElement
     createElementNS(namespaceURI: "http://www.w3.org/2000/svg", qualifiedName: "a"): SVGAElement
     createElementNS(namespaceURI: "http://www.w3.org/2000/svg", qualifiedName: "circle"): SVGCircleElement
     createElementNS(namespaceURI: "http://www.w3.org/2000/svg", qualifiedName: "clipPath"): SVGClipPathElement
@@ -2985,7 +2986,7 @@ interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEven
       * @param elementId String that specifies the ID value. Case-insensitive.
       */
     getElementById(elementId: string): HTMLElement;
-    getElementsByClassName(classNames: string): NodeListOf<Element>;
+    getElementsByClassName(classNames: string): HTMLCollectionOf<Element>;
     /**
       * Gets a collection of objects based on the value of the NAME or ID attribute.
       * @param elementName Gets a collection of objects based on the value of the NAME or ID attribute.
@@ -3172,7 +3173,9 @@ interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEven
     getElementsByTagName(tagname: "x-ms-webview"): NodeListOf<MSHTMLWebViewElement>;
     getElementsByTagName(tagname: "xmp"): NodeListOf<HTMLPreElement>;
     getElementsByTagName(tagname: string): NodeListOf<Element>;
-    getElementsByTagNameNS(namespaceURI: string, localName: string): NodeListOf<Element>;
+    getElementsByTagNameNS(namespaceURI: "http://www.w3.org/1999/xhtml", localName: string): HTMLCollectionOf<HTMLElement>;
+    getElementsByTagNameNS(namespaceURI: "http://www.w3.org/2000/svg", localName: string): HTMLCollectionOf<SVGElement>;
+    getElementsByTagNameNS(namespaceURI: string, localName: string): HTMLCollectionOf<Element>;
     /**
       * Returns an object representing the current selection of the document that is loaded into the object displaying a webpage.
       */
@@ -3642,7 +3645,9 @@ interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelec
     getElementsByTagName(name: "x-ms-webview"): NodeListOf<MSHTMLWebViewElement>;
     getElementsByTagName(name: "xmp"): NodeListOf<HTMLPreElement>;
     getElementsByTagName(name: string): NodeListOf<Element>;
-    getElementsByTagNameNS(namespaceURI: string, localName: string): NodeListOf<Element>;
+    getElementsByTagNameNS(namespaceURI: "http://www.w3.org/1999/xhtml", localName: string): HTMLCollectionOf<HTMLElement>;
+    getElementsByTagNameNS(namespaceURI: "http://www.w3.org/2000/svg", localName: string): HTMLCollectionOf<SVGElement>;
+    getElementsByTagNameNS(namespaceURI: string, localName: string): HTMLCollectionOf<Element>;
     hasAttribute(name: string): boolean;
     hasAttributeNS(namespaceURI: string, localName: string): boolean;
     msGetRegionContent(): MSRangeCollection;
diff --git a/inputfiles/addedTypes.json b/inputfiles/addedTypes.json
index f5be2432f..984d2be72 100644
--- a/inputfiles/addedTypes.json
+++ b/inputfiles/addedTypes.json
@@ -220,6 +220,7 @@
         "name": "createElementNS",
         "interface": "Document",
         "signatures": [
+            "createElementNS(namespaceURI: \"http://www.w3.org/1999/xhtml\", qualifiedName: string): HTMLElement",
             "createElementNS(namespaceURI: \"http://www.w3.org/2000/svg\", qualifiedName: \"a\"): SVGAElement",
             "createElementNS(namespaceURI: \"http://www.w3.org/2000/svg\", qualifiedName: \"circle\"): SVGCircleElement",
             "createElementNS(namespaceURI: \"http://www.w3.org/2000/svg\", qualifiedName: \"clipPath\"): SVGClipPathElement",
diff --git a/inputfiles/overridingTypes.json b/inputfiles/overridingTypes.json
index f570e0f23..d0616b08f 100644
--- a/inputfiles/overridingTypes.json
+++ b/inputfiles/overridingTypes.json
@@ -95,12 +95,16 @@
     {
         "kind": "method",
         "name": "getElementsByTagNameNS",
-        "signatures": ["getElementsByTagNameNS(namespaceURI: string, localName: string): NodeListOf<Element>"]
+        "signatures": [
+            "getElementsByTagNameNS(namespaceURI: \"http://www.w3.org/1999/xhtml\", localName: string): HTMLCollectionOf<HTMLElement>",
+            "getElementsByTagNameNS(namespaceURI: \"http://www.w3.org/2000/svg\", localName: string): HTMLCollectionOf<SVGElement>",
+            "getElementsByTagNameNS(namespaceURI: string, localName: string): HTMLCollectionOf<Element>"
+        ]
     },
     {
         "kind": "method",
         "name": "getElementsByClassName",
-        "signatures": ["getElementsByClassName(classNames: string): NodeListOf<Element>"]
+        "signatures": ["getElementsByClassName(classNames: string): HTMLCollectionOf<Element>"]
     },
     {
         "kind": "method",