diff --git a/baselines/dom.generated.d.ts b/baselines/dom.generated.d.ts
index 5845ef5e4..0e6ab6258 100644
--- a/baselines/dom.generated.d.ts
+++ b/baselines/dom.generated.d.ts
@@ -76,6 +76,7 @@ interface DoubleRange {
 }
 
 interface EventInit {
+    scoped?: boolean;
     bubbles?: boolean;
     cancelable?: boolean;
 }
@@ -2291,7 +2292,7 @@ declare var DeviceRotationRate: {
     new(): DeviceRotationRate;
 }
 
-interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEvent, ParentNode {
+interface Document extends Node, GlobalEventHandlers, NodeSelector, DocumentEvent, ParentNode, DocumentOrShadowRoot {
     /**
       * Sets or gets the URL for the current document. 
       */
@@ -3467,6 +3468,9 @@ interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelec
     readonly scrollWidth: number;
     readonly tagName: string;
     innerHTML: string;
+    readonly assignedSlot: HTMLSlotElement | null;
+    slot: string;
+    readonly shadowRoot: ShadowRoot | null;
     getAttribute(name: string): string | null;
     getAttributeNS(namespaceURI: string, localName: string): string;
     getAttributeNode(name: string): Attr;
@@ -3688,6 +3692,7 @@ interface Element extends Node, GlobalEventHandlers, ElementTraversal, NodeSelec
     insertAdjacentElement(position: string, insertedElement: Element): Element | null;
     insertAdjacentHTML(where: string, html: string): void;
     insertAdjacentText(where: string, text: string): void;
+    attachShadow(shadowRootInitDict: ShadowRootInit): ShadowRoot;
     addEventListener(type: "MSGestureChange", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureDoubleTap", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
     addEventListener(type: "MSGestureEnd", listener: (this: this, ev: MSGestureEvent) => any, useCapture?: boolean): void;
@@ -3759,10 +3764,12 @@ interface Event {
     readonly target: EventTarget;
     readonly timeStamp: number;
     readonly type: string;
+    readonly scoped: boolean;
     initEvent(eventTypeArg: string, canBubbleArg: boolean, cancelableArg: boolean): void;
     preventDefault(): void;
     stopImmediatePropagation(): void;
     stopPropagation(): void;
+    deepPath(): EventTarget[];
     readonly AT_TARGET: number;
     readonly BUBBLING_PHASE: number;
     readonly CAPTURING_PHASE: number;
@@ -11521,6 +11528,7 @@ declare var SubtleCrypto: {
 
 interface Text extends CharacterData {
     readonly wholeText: string;
+    readonly assignedSlot: HTMLSlotElement | null;
     splitText(offset: number): Text;
 }
 
@@ -14247,6 +14255,33 @@ interface ParentNode {
     readonly childElementCount: number;
 }
 
+interface DocumentOrShadowRoot {
+    readonly activeElement: Element | null;
+    readonly stylesheets: StyleSheetList;
+    getSelection(): Selection | null;
+    elementFromPoint(x: number, y: number): Element | null;
+    elementsFromPoint(x: number, y: number): Element[];
+}
+
+interface ShadowRoot extends DocumentOrShadowRoot, DocumentFragment {
+    readonly host: Element;
+    innerHTML: string;
+}
+
+interface ShadowRootInit {
+    mode: 'open'|'closed';
+    delegatesFocus?: boolean;
+}
+
+interface HTMLSlotElement extends HTMLElement {
+    name: string;
+    assignedNodes(options?: AssignedNodesOptions): Node[];
+}
+
+interface AssignedNodesOptions {
+    flatten?: boolean;
+}
+
 declare type EventListenerOrEventListenerObject = EventListener | EventListenerObject;
 
 interface ErrorEventHandler {
diff --git a/baselines/webworker.generated.d.ts b/baselines/webworker.generated.d.ts
index d6edcc4f5..14117a9a5 100644
--- a/baselines/webworker.generated.d.ts
+++ b/baselines/webworker.generated.d.ts
@@ -8,6 +8,7 @@ interface Algorithm {
 }
 
 interface EventInit {
+    scoped?: boolean;
     bubbles?: boolean;
     cancelable?: boolean;
 }
@@ -242,10 +243,12 @@ interface Event {
     readonly target: EventTarget;
     readonly timeStamp: number;
     readonly type: string;
+    readonly scoped: boolean;
     initEvent(eventTypeArg: string, canBubbleArg: boolean, cancelableArg: boolean): void;
     preventDefault(): void;
     stopImmediatePropagation(): void;
     stopPropagation(): void;
+    deepPath(): EventTarget[];
     readonly AT_TARGET: number;
     readonly BUBBLING_PHASE: number;
     readonly CAPTURING_PHASE: number;
diff --git a/inputfiles/addedTypes.json b/inputfiles/addedTypes.json
index 94c1a74b5..52ee0ee42 100644
--- a/inputfiles/addedTypes.json
+++ b/inputfiles/addedTypes.json
@@ -1155,7 +1155,7 @@
         "type": "string"
     },
     {
-        "kind": "interface", 
+        "kind": "interface",
         "name": "ParentNode",
         "flavor": "DOM",
         "properties": [
@@ -1220,5 +1220,149 @@
         "interface": "CanvasPattern",
         "name": "setTransform",
         "signatures": ["setTransform(matrix: SVGMatrix): void"]
+    },
+    {
+        "kind": "interface",
+        "name": "DocumentOrShadowRoot",
+        "flavor": "DOM",
+        "methods": [
+            {
+                "name": "getSelection",
+                "signatures": ["getSelection(): Selection | null"]
+            },
+            {
+                "name": "elementFromPoint",
+                "signatures": ["elementFromPoint(x: number, y: number): Element | null"]
+            },
+            {
+                "name": "elementsFromPoint",
+                "signatures": ["elementsFromPoint(x: number, y: number): Element[]"]
+            }
+        ],
+        "properties": [
+            {
+                "name": "activeElement",
+                "type": "Element | null",
+                "readonly": true
+            },
+            {
+                "name": "stylesheets",
+                "type": "StyleSheetList",
+                "readonly": true
+            }
+        ]
+    },
+    {
+        "kind": "interface",
+        "name": "ShadowRoot",
+        "extends": "DocumentOrShadowRoot, DocumentFragment",
+        "flavor": "DOM",
+        "properties": [
+            {
+                "name": "host",
+                "type": "Element",
+                "readonly": true
+            },
+            {
+                "name": "innerHTML",
+                "type": "string"
+            }
+        ]
+    },
+    {
+        "kind": "method",
+        "interface": "Element",
+        "name": "attachShadow",
+        "signatures": ["attachShadow(shadowRootInitDict: ShadowRootInit): ShadowRoot"]
+    },
+    {
+        "kind": "property",
+        "interface": "Element",
+        "name": "assignedSlot",
+        "type": "HTMLSlotElement | null",
+        "readonly": true
+    },
+    {
+        "kind": "property",
+        "interface": "Element",
+        "name": "slot",
+        "type": "string"
+    },
+    {
+        "kind": "property",
+        "interface": "Element",
+        "name": "shadowRoot",
+        "type": "ShadowRoot | null",
+        "readonly": true
+    },
+    {
+        "kind": "interface",
+        "name": "ShadowRootInit",
+        "flavor": "DOM",
+        "properties": [
+            {
+                "name": "mode",
+                "type": "'open'|'closed'"
+            },
+            {
+                "name": "delegatesFocus?",
+                "type": "boolean"
+            }
+        ]
+    },
+    {
+        "kind": "property",
+        "interface": "Text",
+        "name": "assignedSlot",
+        "type": "HTMLSlotElement | null",
+        "readonly": true
+    },
+    {
+        "kind": "interface",
+        "name": "HTMLSlotElement",
+        "extends": "HTMLElement",
+        "flavor": "DOM",
+        "properties": [
+            {
+                "name": "name",
+                "type": "string"
+            }
+        ],
+        "methods": [
+            {
+                "name": "assignedNodes",
+                "signatures": ["assignedNodes(options?: AssignedNodesOptions): Node[]"]
+            }
+        ]
+    },
+    {
+        "kind": "interface",
+        "name": "AssignedNodesOptions",
+        "flavor": "DOM",
+        "properties": [
+            {
+                "name": "flatten?",
+                "type": "boolean"
+            }
+        ]
+    },
+    {
+        "kind": "property",
+        "interface": "EventInit",
+        "name": "scoped?",
+        "type": "boolean"
+    },
+    {
+        "kind": "property",
+        "interface": "Event",
+        "name": "scoped",
+        "type": "boolean",
+        "readonly": true
+    },
+    {
+        "kind": "method",
+        "interface": "Event",
+        "name": "deepPath",
+        "signatures": ["deepPath(): EventTarget[]"]
     }
 ]
diff --git a/inputfiles/overridingTypes.json b/inputfiles/overridingTypes.json
index 8664281f3..b9b40d469 100644
--- a/inputfiles/overridingTypes.json
+++ b/inputfiles/overridingTypes.json
@@ -924,5 +924,10 @@
         "interface": "XPathExpression",
         "name": "evaluate",
         "signatures": ["evaluate(contextNode: Node, type: number, result: XPathResult | null): XPathResult"]
+    },
+    {
+        "kind": "extends",
+        "baseInterface": "Node, GlobalEventHandlers, NodeSelector, DocumentEvent, ParentNode, DocumentOrShadowRoot",
+        "interface": "Document"
     }
  ]