diff --git a/lib/legacy/legacy-element-mixin.js b/lib/legacy/legacy-element-mixin.js
index 151a13fa56..3fe3280256 100644
--- a/lib/legacy/legacy-element-mixin.js
+++ b/lib/legacy/legacy-element-mixin.js
@@ -23,6 +23,8 @@ import { get } from '../utils/path.js';
 
 let styleInterface = window.ShadyCSS;
 
+let wrap = (n) => n;
+
 /**
  * Element class mixin that provides Polymer's "legacy" API intended to be
  * backward-compatible to the greatest extent possible with the API
@@ -490,7 +492,7 @@ export const LegacyElementMixin = dedupingMixin((base) => {
      * @this {Element}
      */
     get domHost() {
-      let root = this.getRootNode();
+      let root = wrap(this).getRootNode();
       return (root instanceof DocumentFragment) ? /** @type {ShadowRoot} */ (root).host : root;
     }
 
@@ -636,8 +638,8 @@ export const LegacyElementMixin = dedupingMixin((base) => {
      */
     isLightDescendant(node) {
       const thisNode = /** @type {Node} */ (this);
-      return thisNode !== node && thisNode.contains(node) &&
-        thisNode.getRootNode() === node.getRootNode();
+      return thisNode !== node && wrap(thisNode).contains(node) &&
+        wrap(thisNode).getRootNode() === wrap(node).getRootNode();
     }
 
     /**
@@ -647,7 +649,7 @@ export const LegacyElementMixin = dedupingMixin((base) => {
      * @return {boolean} true if node is in this element's local DOM tree.
      */
     isLocalDescendant(node) {
-      return this.root === node.getRootNode();
+      return this.root === wrap(node).getRootNode();
     }
 
     /**
@@ -825,10 +827,10 @@ export const LegacyElementMixin = dedupingMixin((base) => {
         bool = !node.hasAttribute(name);
       }
       if (bool) {
-        node.setAttribute(name, '');
+        wrap(node).setAttribute(name, '');
         return true;
       } else {
-        node.removeAttribute(name);
+        wrap(node).removeAttribute(name);
         return false;
       }
     }
@@ -983,6 +985,22 @@ export const LegacyElementMixin = dedupingMixin((base) => {
 
   }
 
+  if (window.ShadyDOM && window.ShadyDOM.inUse && window.ShadyDOM.noPatch) {
+    wrap = ShadyDOM.wrap;
+
+    LegacyElement.prototype._attachDom = function(dom) {
+      const w = this.__wrapper = ShadyDOM.wrap(this);
+      if (dom) {
+        if (!w.shadowRoot) {
+          w.attachShadow({mode: 'open'});
+        }
+        w.shadowRoot.appendChild(dom);
+        return w.shadowRoot;
+      }
+      return null;
+    };
+  }
+
   LegacyElement.prototype.is = '';
 
   return LegacyElement;
diff --git a/lib/legacy/polymer.dom.js b/lib/legacy/polymer.dom.js
index 392e910d36..dd5d961ee1 100644
--- a/lib/legacy/polymer.dom.js
+++ b/lib/legacy/polymer.dom.js
@@ -41,7 +41,7 @@ export const matchesSelector = function(node, selector) {
  * `target` is a `Node`.
  *
  */
-export class DomApi {
+export let DomApi = class {
 
   /**
    * @param {Node} node Node for which to create a Polymer.dom helper object.
@@ -194,7 +194,7 @@ export class DomApi {
     let node = this.node;
     return node._activeElement !== undefined ? node._activeElement : node.activeElement;
   }
-}
+};
 
 function forwardMethods(proto, methods) {
   for (let i=0; i < methods.length; i++) {
@@ -368,22 +368,103 @@ DomApi.prototype.textContent;
 /** @type {string} */
 DomApi.prototype.innerHTML;
 
-forwardMethods(DomApi.prototype, [
-  'cloneNode', 'appendChild', 'insertBefore', 'removeChild',
-  'replaceChild', 'setAttribute', 'removeAttribute',
-  'querySelector', 'querySelectorAll'
-]);
 
-forwardReadOnlyProperties(DomApi.prototype, [
-  'parentNode', 'firstChild', 'lastChild',
-  'nextSibling', 'previousSibling', 'firstElementChild',
-  'lastElementChild', 'nextElementSibling', 'previousElementSibling',
-  'childNodes', 'children', 'classList'
-]);
+if (window.ShadyDOM && window.ShadyDOM.inUse && window.ShadyDOM.noPatch) {
+  class Wrapper extends ShadyDOM.Wrapper {
+    observeNodes(callback) {
+      return new FlattenedNodesObserver(
+          /** @type {!HTMLElement} */(this.node), callback, dom);
+    }
+
+    unobserveNodes(observerHandle) {
+      observerHandle.disconnect();
+    }
+
+    notifyObserver() {}
+
+    deepContains(node) {
+      if (this.contains(node)) {
+        return true;
+      }
+      let n = node;
+      let doc = node.ownerDocument;
+      // walk from node to `this` or `document`
+      while (n && n !== doc && n !== this.node) {
+        // use logical parentnode, or native ShadowRoot host
+        n = this.parentNode || n.host;
+      }
+      return n === this.node;
+    }
+
+    getOwnerRoot() {
+      return this.getRootNode();
+    }
+
+    getDistributedNodes() {
+      return (this.node.localName === 'slot') ?
+        this.assignedNodes({flatten: true}) :
+        [];
+    }
+
+    getDestinationInsertionPoints() {
+      let ip$ = [];
+      let n = this.assignedSlot;
+      while (n) {
+        ip$.push(n);
+        n = ShadyDOM.wrap(n).assignedSlot;
+      }
+      return ip$;
+    }
+
+    importNode(node, deep) {
+      let doc = this.node instanceof Document ? this.node :
+        this.node.ownerDocument;
+      return ShadyDOM.wrap(doc).importNode(node, deep);
+    }
+
+    getEffectiveChildNodes() {
+      return FlattenedNodesObserver.getFlattenedNodes(
+          /** @type {!HTMLElement} */ (this), dom);
+    }
+
+    queryDistributedElements(selector) {
+      let c$ = this.getEffectiveChildNodes();
+      let list = [];
+      for (let i=0, l=c$.length, c; (i<l) && (c=c$[i]); i++) {
+        if ((c.nodeType === Node.ELEMENT_NODE) &&
+            matchesSelector(c, selector)) {
+          list.push(c);
+        }
+      }
+      return list;
+    }
+
+    get activeElement() {
+      let node = this.node;
+      return node._activeElement !== undefined ? node._activeElement : node.activeElement;
+    }
+  }
+
+  DomApi = Wrapper;
+} else {
 
-forwardProperties(DomApi.prototype, [
-  'textContent', 'innerHTML'
-]);
+  forwardMethods(DomApi.prototype, [
+    'cloneNode', 'appendChild', 'insertBefore', 'removeChild',
+    'replaceChild', 'setAttribute', 'removeAttribute',
+    'querySelector', 'querySelectorAll'
+  ]);
+
+  forwardReadOnlyProperties(DomApi.prototype, [
+    'parentNode', 'firstChild', 'lastChild',
+    'nextSibling', 'previousSibling', 'firstElementChild',
+    'lastElementChild', 'nextElementSibling', 'previousElementSibling',
+    'childNodes', 'children', 'classList'
+  ]);
+
+  forwardProperties(DomApi.prototype, [
+    'textContent', 'innerHTML'
+  ]);
+}
 
 /**
  * Legacy DOM and Event manipulation API wrapper factory used to abstract
@@ -400,6 +481,9 @@ forwardProperties(DomApi.prototype, [
  * @return {!DomApi|!EventApi} Wrapper providing either node API or event API
  */
 export const dom = function(obj) {
+  if (obj instanceof DomApi || obj instanceof EventApi) {
+    return obj;
+  }
   obj = obj || document;
   if (!obj.__domApi) {
     let helper;
diff --git a/lib/utils/flattened-nodes-observer.js b/lib/utils/flattened-nodes-observer.js
index 25ff69a1a4..7a48f4f7b6 100644
--- a/lib/utils/flattened-nodes-observer.js
+++ b/lib/utils/flattened-nodes-observer.js
@@ -63,7 +63,7 @@ function isSlot(node) {
  * @summary Class that listens for changes (additions or removals) to
  * "flattened nodes" on a given `node`.
  */
-export class FlattenedNodesObserver {
+export let FlattenedNodesObserver = class {
 
   /**
    * Returns the list of flattened nodes for the given `node`.
@@ -79,15 +79,17 @@ export class FlattenedNodesObserver {
    * @return {!Array<!Node>} The list of flattened nodes for the given `node`.
    * @nocollapse See https://github.com/google/closure-compiler/issues/2763
    */
-  static getFlattenedNodes(node) {
+  // eslint-disable-next-line
+  static getFlattenedNodes(node, wrapper = (n) => n) {
+    const wrapped = wrapper(node);
     if (isSlot(node)) {
       node = /** @type {!HTMLSlotElement} */(node); // eslint-disable-line no-self-assign
-      return node.assignedNodes({flatten: true});
+      return wrapped.assignedNodes({flatten: true});
     } else {
-      return Array.from(node.childNodes).map((node) => {
+      return Array.from(wrapped.childNodes).map((node) => {
         if (isSlot(node)) {
           node = /** @type {!HTMLSlotElement} */(node); // eslint-disable-line no-self-assign
-          return node.assignedNodes({flatten: true});
+          return wrapper(node).assignedNodes({flatten: true});
         } else {
           return [node];
         }
@@ -100,11 +102,13 @@ export class FlattenedNodesObserver {
    * @param {?function(this: Element, { target: !HTMLElement, addedNodes: !Array<!Element>, removedNodes: !Array<!Element> }):void} callback Function called when there are additions
    * or removals from the target's list of flattened nodes.
    */
-  constructor(target, callback) {
+  // eslint-disable-next-line
+  constructor(target, callback, wrapper = n=> n) {
     /**
      * @type {MutationObserver}
      * @private
      */
+    this._wrap = wrapper;
     this._shadyChildrenObserver = null;
     /**
      * @type {MutationObserver}
@@ -132,6 +136,10 @@ export class FlattenedNodesObserver {
     this._schedule();
   }
 
+  _wrap(node) {
+    return node;
+  }
+
   /**
    * Activates an observer. This method is automatically called when
    * a `FlattenedNodesObserver` is created. It should only be called to
@@ -142,9 +150,9 @@ export class FlattenedNodesObserver {
   connect() {
     if (isSlot(this._target)) {
       this._listenSlots([this._target]);
-    } else if (this._target.children) {
+    } else if (this._wrap(this._target).children) {
       this._listenSlots(
-          /** @type {!NodeList<!Node>} */ (this._target.children));
+          /** @type {!NodeList<!Node>} */ (this._wrap(this._target).children));
       if (window.ShadyDOM) {
         this._shadyChildrenObserver =
           ShadyDOM.observeChildren(this._target, (mutations) => {
@@ -172,9 +180,9 @@ export class FlattenedNodesObserver {
   disconnect() {
     if (isSlot(this._target)) {
       this._unlistenSlots([this._target]);
-    } else if (this._target.children) {
+    } else if (this._wrap(this._target).children) {
       this._unlistenSlots(
-          /** @type {!NodeList<!Node>} */ (this._target.children));
+          /** @type {!NodeList<!Node>} */ (this._wrap(this._target).children));
       if (window.ShadyDOM && this._shadyChildrenObserver) {
         ShadyDOM.unobserveChildren(this._shadyChildrenObserver);
         this._shadyChildrenObserver = null;
@@ -305,4 +313,15 @@ export class FlattenedNodesObserver {
     }
   }
 
-}
+};
+
+if (window.ShadyDOM && window.ShadyDOM.inUse && window.ShadyDOM.noPatch) {
+  FlattenedNodesObserver = class extends FlattenedNodesObserver {
+
+    static _wrap(node) {
+      return Polymer.dom(node);
+    }
+
+  };
+
+}
\ No newline at end of file
diff --git a/test/unit/polymer-dom-unpatch.html b/test/unit/polymer-dom-unpatch.html
new file mode 100644
index 0000000000..d08c1eb527
--- /dev/null
+++ b/test/unit/polymer-dom-unpatch.html
@@ -0,0 +1,352 @@
+<!doctype html>
+<!--
+@license
+Copyright (c) 2017 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+-->
+<html>
+<head>
+  <meta charset="utf-8">
+  <script>
+    ShadyDOM = {force: true, noPatch: true};
+  </script>
+  <script src="../../node_modules/@webcomponents/webcomponentsjs/webcomponents-lite.js"></script>
+  <script src="wct-browser-config.js"></script>
+  <script src="../../node_modules/wct-browser-legacy/browser.js"></script>
+  <script type="module" src="../../polymer-legacy.js"></script>
+</head>
+<body>
+
+  <dom-module id="x-slot">
+    <template>
+      <div id="container"><slot id="slot"></slot></div>
+    </template>
+    <script type="module">
+import { Polymer } from '../../polymer-legacy.js';
+Polymer({
+  is: 'x-slot'
+});
+</script>
+  </dom-module>
+
+  <dom-module id="x-container-slot">
+    <template>
+      <x-slot id="container"><div id="first">first</div><slot id="slot"></slot><div id="last">last</div></x-slot>
+    </template>
+    <script type="module">
+import { Polymer } from '../../polymer-legacy.js';
+Polymer({
+  is: 'x-container-slot'
+});
+</script>
+  </dom-module>
+
+  <dom-module id="x-event-scoped">
+    <template>
+      <div id="scoped"></div>
+    </template>
+    <script type="module">
+import { Polymer } from '../../polymer-legacy.js';
+Polymer({
+  is: 'x-event-scoped',
+  fireComposed: function() {
+    return this.fire('composed', null, {node: this.$.scoped});
+  }
+});
+</script>
+  </dom-module>
+
+  <dom-module id="x-focusable-in-shadow">
+    <template>
+      <input id="focusable"></input>
+    </template>
+    <script type="module">
+import { Polymer } from '../../polymer-legacy.js';
+Polymer({
+  is: 'x-focusable-in-shadow'
+});
+</script>
+  </dom-module>
+
+   <test-fixture id="scoped">
+    <template>
+      <x-event-scoped></x-event-scoped>
+    </template>
+  </test-fixture>
+
+  <test-fixture id="slot">
+    <template>
+      <x-container-slot></x-container-slot>
+    </template>
+  </test-fixture>
+
+  <test-fixture id="focusableInShadow">
+    <template>
+      <x-focusable-in-shadow></x-focusable-in-shadow>
+    </template>
+  </test-fixture>
+
+<script type="module">
+import { dom } from '../../lib/legacy/polymer.dom.js';
+import { useShadow, useNativeCustomElements, useNativeCSSProperties } from '../../lib/utils/settings.js';
+
+suite('extended dom api', function() {
+  test('getEffectiveChildNodes', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(dom(el).getEffectiveChildNodes(),
+      [div]);
+    assert.deepEqual(dom(el.$.container).getEffectiveChildNodes(),
+      [el.$.first, div, el.$.last]);
+    assert.deepEqual(dom(el.$.container.$.container).getEffectiveChildNodes(),
+      [el.$.first, div, el.$.last]);
+  });
+
+  test('queryDistributedElements', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(dom(el).queryDistributedElements('foo'),
+      []);
+    assert.deepEqual(dom(el).queryDistributedElements('div'),
+      [div]);
+    assert.deepEqual(dom(el.$.container).queryDistributedElements('#first'),
+      [el.$.first]);
+    assert.deepEqual(dom(el.$.container.$.container).queryDistributedElements('#last'),
+      [el.$.last]);
+  });
+
+});
+
+suite('distribution', function() {
+  test('getDistributedNodes', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(dom(el.$.slot).getDistributedNodes(), [div]);
+    assert.deepEqual(dom(el.$.container.$.slot).getDistributedNodes(),
+      [el.$.first, div, el.$.last]);
+  });
+
+  test('getDestinationInsertionPoints', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(dom(el.$.first).getDestinationInsertionPoints(),
+      [el.$.container.$.slot]);
+    assert.deepEqual(dom(div).getDestinationInsertionPoints(),
+      [el.$.slot, el.$.container.$.slot]);
+  });
+});
+
+// suite('events', function() {
+
+//   test('localTarget, rootTarget, path', function(done) {
+//     var el = fixture('scoped');
+//     el.addEventListener('composed', function(e) {
+//       assert.equal(dom(e).rootTarget, el.$.scoped);
+//       assert.equal(dom(e).localTarget, el);
+//       let nodes = [];
+//       let p = el.$.scoped;
+//       while (p) {
+//         nodes.push(p);
+//         p = p.parentNode || p.host;
+//       }
+//       nodes.push(window);
+//       assert.deepEqual(Array.from(dom(e).path), nodes);
+//       done();
+//     });
+//     el.fireComposed();
+//   });
+
+// });
+
+// suite('activeElement getter', function() {
+//   test('Retrieves `_activeElement` (ShadyDOM) or `activeElement`.', function() {
+//     var focusableInShadow = fixture('focusableInShadow');
+//     focusableInShadow.$.focusable.focus();
+//     var rootNode = focusableInShadow.getRootNode();
+//     assert.equal(dom(rootNode).activeElement, focusableInShadow);
+//     assert.equal(dom(focusableInShadow.shadowRoot).activeElement, focusableInShadow.$.focusable);
+//   });
+// });
+
+suite('legacy api', function() {
+  test('getEffectiveChildNodes', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    var t = document.createTextNode('yo');
+    dom(el).appendChild(div);
+    dom(el).appendChild(t);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.getEffectiveChildNodes(),
+      [div, t]);
+    assert.deepEqual(el.$.container.getEffectiveChildNodes(),
+      [el.$.first, div, t, el.$.last]);
+  });
+
+  test('getEffectiveChildren', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.getEffectiveChildNodes(),
+      [div]);
+    assert.deepEqual(el.$.container.getEffectiveChildNodes(),
+      [el.$.first, div, el.$.last]);
+  });
+
+  test('getEffectiveTextContent', function() {
+    var el = fixture('slot');
+    var t1 = document.createTextNode('a');
+    var t2 = document.createTextNode('b');
+    dom(el).appendChild(t1);
+    dom(el).appendChild(t2);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.getEffectiveTextContent(), 'ab');
+    assert.deepEqual(el.$.container.getEffectiveTextContent(), 'firstablast');
+  });
+
+  test('getContentChildNodes', function() {
+    var el = fixture('slot');
+    var div1 = document.createElement('div');
+    var t = document.createTextNode('');
+    var div2 = document.createElement('div');
+    dom(el).appendChild(div1);
+    dom(el).appendChild(t);
+    dom(el).appendChild(div2);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.getContentChildNodes(),
+      [div1, t, div2]);
+    assert.deepEqual(el.getContentChildNodes('slot'),
+      [div1, t, div2]);
+  });
+
+  test('getContentChildren', function() {
+    var el = fixture('slot');
+    var div1 = document.createElement('div');
+    var t = document.createTextNode('');
+    var div2 = document.createElement('div');
+    dom(el).appendChild(div1);
+    dom(el).appendChild(t);
+    dom(el).appendChild(div2);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.getContentChildren(),
+      [div1, div2]);
+    assert.deepEqual(el.getContentChildren('slot'),
+      [div1, div2]);
+  });
+
+  test('queryDistributedElements', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.queryDistributedElements('foo'),
+      []);
+    assert.deepEqual(el.queryDistributedElements('div'),
+      [div]);
+    assert.deepEqual(el.$.container.queryDistributedElements('#first'),
+      [el.$.first]);
+  });
+
+  test('queryEffectiveChildren', function() {
+    var el = fixture('slot');
+    var div = document.createElement('div');
+    dom(el).appendChild(div);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.equal(el.queryEffectiveChildren('foo'),
+      null);
+    assert.deepEqual(el.queryEffectiveChildren('div'),
+      div);
+    assert.deepEqual(el.$.container.queryEffectiveChildren('#first'),
+      el.$.first);
+  });
+
+  test('queryAllEffectiveChildren', function() {
+    var el = fixture('slot');
+    var div1 = document.createElement('div');
+    var div2 = document.createElement('div');
+    dom(el).appendChild(div1);
+    dom(el).appendChild(div2);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.deepEqual(el.queryAllEffectiveChildren('foo'),
+      []);
+    assert.deepEqual(el.queryAllEffectiveChildren('div'),
+      [div1, div2]);
+    assert.deepEqual(el.$.container.queryAllEffectiveChildren('div'),
+      [el.$.first, div1, div2, el.$.last]);
+  });
+
+  test('isLightDescendant', function() {
+    var el = fixture('slot');
+    var div1 = document.createElement('div');
+    dom(el).appendChild(div1);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.equal(el.isLightDescendant(div1), true);
+    assert.equal(el.isLightDescendant(el.$.container), false);
+  });
+
+  test('isLocalDescendant', function() {
+    var el = fixture('slot');
+    var div1 = document.createElement('div');
+    dom(el).appendChild(div1);
+    if (window.ShadyDOM) {
+      ShadyDOM.flush();
+    }
+    assert.equal(el.isLocalDescendant(div1), false);
+    assert.equal(el.isLocalDescendant(el.$.container), true);
+  });
+
+  test('domHost', function() {
+    var el = fixture('slot');
+    assert.equal(el.domHost, document);
+    assert.equal(el.$.container.domHost, el);
+  });
+
+  test('legacy settings', function() {
+    assert.equal(useShadow, !(window.ShadyDOM));
+    assert.equal(useNativeCustomElements, !(window.customElements.polyfillWrapFlushCallback));
+    assert.equal(useNativeCSSProperties, Boolean(!window.ShadyCSS || window.ShadyCSS.nativeCss));
+  });
+
+});
+</script>
+
+</body>
+</html>