diff --git a/lib/legacy/polymer-fn.js b/lib/legacy/polymer-fn.js
index 2296c820d7..3651dcc44c 100644
--- a/lib/legacy/polymer-fn.js
+++ b/lib/legacy/polymer-fn.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import { Class } from './class.js';
 
-import { Polymer } from '../utils/boot.js';
+import '../utils/boot.js';
 
 /**
  * Legacy class factory and registration helper for defining Polymer
diff --git a/test/smoke/behavior-mixin.html b/test/smoke/behavior-mixin.html
index 3280def318..b8cdaa7873 100644
--- a/test/smoke/behavior-mixin.html
+++ b/test/smoke/behavior-mixin.html
@@ -23,7 +23,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { DomModule } from '../../lib/elements/dom-module.js';
 import { mixinBehaviors } from '../../lib/legacy/class.js';
 /** @polymerBehavior */
diff --git a/test/smoke/data-table.html b/test/smoke/data-table.html
index 85987138fa..d992b065fd 100644
--- a/test/smoke/data-table.html
+++ b/test/smoke/data-table.html
@@ -48,7 +48,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'data-popup'
 });
@@ -98,7 +98,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'data-cell',
   properties: {
@@ -160,7 +160,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'data-row',
   properties: {
diff --git a/test/smoke/passive-gestures.html b/test/smoke/passive-gestures.html
index 24d2726e0f..5f15dcb1bb 100644
--- a/test/smoke/passive-gestures.html
+++ b/test/smoke/passive-gestures.html
@@ -41,7 +41,7 @@
   </dom-module>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-passive',
   listeners: {
@@ -62,4 +62,4 @@
 </script>
   <x-passive></x-passive>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/test/smoke/style-props/src/elements.js b/test/smoke/style-props/src/elements.js
index dbb1fb27c0..a0663a98a1 100644
--- a/test/smoke/style-props/src/elements.js
+++ b/test/smoke/style-props/src/elements.js
@@ -1,5 +1,5 @@
 import './elements-defaults.js';
-import { Polymer } from '../../../../lib/utils/boot.js';
+import { Polymer } from '../../../../lib/legacy/polymer-fn.js';
 import { html } from '../../../../lib/utils/html-tag.js';
 Polymer({
   _template: html`
diff --git a/test/smoke/style-props/src/scopes.js b/test/smoke/style-props/src/scopes.js
index 97d7eee9f0..60d2a2c3a4 100644
--- a/test/smoke/style-props/src/scopes.js
+++ b/test/smoke/style-props/src/scopes.js
@@ -1,6 +1,6 @@
 import './settings.js';
 import './elements.js';
-import { Polymer } from '../../../../lib/utils/boot.js';
+import { Polymer } from '../../../../lib/legacy/polymer-fn.js';
 import { html } from '../../../../lib/utils/html-tag.js';
 import { dom } from '../../../../lib/legacy/polymer.dom.js';
 
diff --git a/test/smoke/style-props/src/settings.js b/test/smoke/style-props/src/settings.js
index 69deaf5653..40bda96654 100644
--- a/test/smoke/style-props/src/settings.js
+++ b/test/smoke/style-props/src/settings.js
@@ -1,4 +1,4 @@
-import { Polymer } from '../../../../lib/utils/boot.js';
+import { Polymer } from '../../../../lib/legacy/polymer-fn.js';
 import { html } from '../../../../lib/utils/html-tag.js';
 const $_documentContainer = document.createElement('div');
 $_documentContainer.setAttribute('style', 'display: none;');
diff --git a/test/unit/array-selector-elements.js b/test/unit/array-selector-elements.js
index 6f8b566280..85c774f37d 100644
--- a/test/unit/array-selector-elements.js
+++ b/test/unit/array-selector-elements.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 Polymer({
   is: 'observe-el',
diff --git a/test/unit/attributes-elements.js b/test/unit/attributes-elements.js
index 96a69ea21c..13070add90 100644
--- a/test/unit/attributes-elements.js
+++ b/test/unit/attributes-elements.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 import { html } from '../../lib/utils/html-tag.js';
 let PropertyTypeBehavior = {
diff --git a/test/unit/behaviors.html b/test/unit/behaviors.html
index 35c26edaa3..cc47cbb1aa 100644
--- a/test/unit/behaviors.html
+++ b/test/unit/behaviors.html
@@ -24,7 +24,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 window.BehaviorA = {
   properties: {
 
@@ -311,7 +311,7 @@
   </test-fixture>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 suite('single behavior element', function() {
   var el;
diff --git a/test/unit/configure.html b/test/unit/configure.html
index 7b15e06c0e..e2f1bbf005 100644
--- a/test/unit/configure.html
+++ b/test/unit/configure.html
@@ -39,7 +39,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
 
   is: 'x-configure-value',
@@ -78,7 +78,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
 
   is: 'x-configure-gchild',
@@ -117,7 +117,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
 
   is: 'x-configure-child',
@@ -185,7 +185,7 @@
   <dom-module id="x-configure-simple-child">
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
 
   is: 'x-configure-simple-child',
@@ -218,7 +218,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
 
   is: 'x-configure-host',
@@ -324,7 +324,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-config-lazy-host',
   properties: {
@@ -350,7 +350,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 function testValueAndChangeHandler(e, value) {
   assert.equal(e.content, value, 'Property does not equal configured value');
diff --git a/test/unit/custom-style-async-import.html b/test/unit/custom-style-async-import.html
index dba3767539..94f5ec3529 100644
--- a/test/unit/custom-style-async-import.html
+++ b/test/unit/custom-style-async-import.html
@@ -28,7 +28,7 @@
     x-client
   </template>
   <script type="module">
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-client'
 });
diff --git a/test/unit/custom-style-async.html b/test/unit/custom-style-async.html
index 4f34d18a2a..fc771f8a63 100644
--- a/test/unit/custom-style-async.html
+++ b/test/unit/custom-style-async.html
@@ -33,7 +33,7 @@
   </dom-module>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-host'
 });
diff --git a/test/unit/custom-style-late.html b/test/unit/custom-style-late.html
index 6671329814..183778bc53 100644
--- a/test/unit/custom-style-late.html
+++ b/test/unit/custom-style-late.html
@@ -42,7 +42,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { afterNextRender } from '../../lib/utils/render-status.js';
 /* global input */
 
diff --git a/test/unit/custom-style-scope-cache.html b/test/unit/custom-style-scope-cache.html
index 650768f0ff..7eec6cda8d 100644
--- a/test/unit/custom-style-scope-cache.html
+++ b/test/unit/custom-style-scope-cache.html
@@ -36,7 +36,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'cache-element'
 });
diff --git a/test/unit/custom-style.html b/test/unit/custom-style.html
index 7d24133f21..e0d50ca535 100644
--- a/test/unit/custom-style.html
+++ b/test/unit/custom-style.html
@@ -415,7 +415,7 @@
   <script type="module">
 import '../../polymer-legacy.js';
 import './custom-style-import.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-baz'
 });
@@ -441,7 +441,7 @@
 import '../../polymer-legacy.js';
 import './custom-style-import.js';
 import { updateStyles } from '../../lib/mixins/element-mixin.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 suite('custom-style', function() {
 
diff --git a/test/unit/debounce.html b/test/unit/debounce.html
index 7166b090d7..e8bbefa32b 100644
--- a/test/unit/debounce.html
+++ b/test/unit/debounce.html
@@ -30,7 +30,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { Debouncer } from '../../lib/utils/debounce.js';
 import { microTask, timeOut, animationFrame, idlePeriod } from '../../lib/utils/async.js';
 Polymer({is: 'x-basic'});
diff --git a/test/unit/dir.html b/test/unit/dir.html
index c39a803c2d..1cab25469f 100644
--- a/test/unit/dir.html
+++ b/test/unit/dir.html
@@ -111,7 +111,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import '../../lib/mixins/dir-mixin.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dir-legacy'});
 </script>
   </dom-module>
@@ -261,4 +261,4 @@
 });
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/test/unit/disable-upgrade.html b/test/unit/disable-upgrade.html
index 77c3a7a99e..14dd626de4 100644
--- a/test/unit/disable-upgrade.html
+++ b/test/unit/disable-upgrade.html
@@ -163,7 +163,7 @@ <h2 id="element">[[prop]]</h2>
     <script type="module">
 import '../../polymer-legacy.js';
 import '../../lib/mixins/disable-upgrade-mixin.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'my-element-legacy',
   properties: {
@@ -275,4 +275,4 @@ <h2 id="element">[[prop]]</h2>
 });
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/test/unit/dom-bind-elements1.js b/test/unit/dom-bind-elements1.js
index 3e471cd3d6..bbb908bc65 100644
--- a/test/unit/dom-bind-elements1.js
+++ b/test/unit/dom-bind-elements1.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 import { html } from '../../lib/utils/html-tag.js';
 Polymer({
diff --git a/test/unit/dom-bind-elements2.js b/test/unit/dom-bind-elements2.js
index 4ae2439458..4993e8c2f6 100644
--- a/test/unit/dom-bind-elements2.js
+++ b/test/unit/dom-bind-elements2.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 Polymer({
   is: 'x-needs-host',
diff --git a/test/unit/dom-if-elements.js b/test/unit/dom-if-elements.js
index dc54d1d557..5f851548ca 100644
--- a/test/unit/dom-if-elements.js
+++ b/test/unit/dom-if-elements.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 import { html } from '../../lib/utils/html-tag.js';
 Polymer({
diff --git a/test/unit/dom-repeat-elements.js b/test/unit/dom-repeat-elements.js
index 263e68ee02..46e2bb73f7 100644
--- a/test/unit/dom-repeat-elements.js
+++ b/test/unit/dom-repeat-elements.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 import { html } from '../../lib/utils/html-tag.js';
 import { MutableData } from '../../lib/mixins/mutable-data.js';
diff --git a/test/unit/dynamic-imports/dynamic-element.js b/test/unit/dynamic-imports/dynamic-element.js
index 34a57bb43e..71bb347809 100644
--- a/test/unit/dynamic-imports/dynamic-element.js
+++ b/test/unit/dynamic-imports/dynamic-element.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import '../../../polymer-legacy.js';
 
-import { Polymer } from '../../../lib/utils/boot.js';
+import { Polymer } from '../../../lib/legacy/polymer-fn.js';
 import { html } from '../../../lib/utils/html-tag.js';
 import { dom } from '../../../lib/legacy/polymer.dom.js';
 Polymer({
diff --git a/test/unit/dynamic-imports/inner-element.js b/test/unit/dynamic-imports/inner-element.js
index f6f01326b3..ae8a735b57 100644
--- a/test/unit/dynamic-imports/inner-element.js
+++ b/test/unit/dynamic-imports/inner-element.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import '../../../polymer-legacy.js';
 
-import { Polymer } from '../../../lib/utils/boot.js';
+import { Polymer } from '../../../lib/legacy/polymer-fn.js';
 import { html } from '../../../lib/utils/html-tag.js';
 Polymer({
   _template: html`
diff --git a/test/unit/dynamic-imports/outer-element.html b/test/unit/dynamic-imports/outer-element.html
index 780ec04a5c..8670c265f9 100644
--- a/test/unit/dynamic-imports/outer-element.html
+++ b/test/unit/dynamic-imports/outer-element.html
@@ -23,7 +23,7 @@
 <script type="module">
 import '../../../polymer-legacy.js';
 import './inner-element.js';
-import { Polymer } from '../../../lib/utils/boot.js';
+import { Polymer } from '../../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'outer-element'
 });
diff --git a/test/unit/events-elements.js b/test/unit/events-elements.js
index 08f989e182..02b5087a8e 100644
--- a/test/unit/events-elements.js
+++ b/test/unit/events-elements.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import { Base } from '../../polymer-legacy.js';
 
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { html } from '../../lib/utils/html-tag.js';
 var EventLoggerImpl = {
   created: function() {
diff --git a/test/unit/gestures-elements.js b/test/unit/gestures-elements.js
index 4410af742a..8a4f75c448 100644
--- a/test/unit/gestures-elements.js
+++ b/test/unit/gestures-elements.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import '../../polymer-legacy.js';
 
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { html } from '../../lib/utils/html-tag.js';
 import { PolymerElement } from '../../polymer-element.js';
 import { GestureEventListeners } from '../../lib/mixins/gesture-event-listeners.js';
diff --git a/test/unit/globals.html b/test/unit/globals.html
index 0546765fc0..cccc63e25d 100644
--- a/test/unit/globals.html
+++ b/test/unit/globals.html
@@ -36,7 +36,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'global-test',
   properties: {
@@ -64,7 +64,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 suite('globals', function() {
 
diff --git a/test/unit/html-tag.html b/test/unit/html-tag.html
index b078cc2366..7ad3b9bb35 100644
--- a/test/unit/html-tag.html
+++ b/test/unit/html-tag.html
@@ -20,7 +20,7 @@
 import '../../polymer-legacy.js';
 import { html, htmlLiteral } from '../../lib/utils/html-tag.js';
 import { PolymerElement } from '../../polymer-element.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 suite('html function', function() {
   test('html makes an HTML template', function() {
     let t = html``;
diff --git a/test/unit/logging.html b/test/unit/logging.html
index 7acb627086..0d697a260c 100644
--- a/test/unit/logging.html
+++ b/test/unit/logging.html
@@ -19,7 +19,7 @@
   <dom-module id="x-logging">
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-logging',
   properties: {
@@ -89,7 +89,7 @@
 suite('_logger', () => {
   test('_log with single parameter', () => {
     const msg = 'log test';
-    const orgConsole = console;      
+    const orgConsole = console;
     const spy = sinon.spy();
     window.console = {
       log: spy
diff --git a/test/unit/mixin-behaviors.html b/test/unit/mixin-behaviors.html
index 37f1fa19f7..5cd82c900a 100644
--- a/test/unit/mixin-behaviors.html
+++ b/test/unit/mixin-behaviors.html
@@ -377,7 +377,7 @@
   </test-fixture>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { mixinBehaviors } from '../../lib/legacy/class.js';
 import { PolymerElement } from '../../polymer-element.js';
 
diff --git a/test/unit/multi-style.html b/test/unit/multi-style.html
index d040de9e6f..dddc182680 100644
--- a/test/unit/multi-style.html
+++ b/test/unit/multi-style.html
@@ -62,7 +62,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { PolymerElement } from '../../polymer-element.js';
 import { DomModule } from '../../lib/elements/dom-module.js';
 suite('elements including multiple styles', function() {
@@ -124,4 +124,4 @@
 });
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/test/unit/path-effects-elements.js b/test/unit/path-effects-elements.js
index 9fa5f4e4fd..2a80f07b3a 100644
--- a/test/unit/path-effects-elements.js
+++ b/test/unit/path-effects-elements.js
@@ -9,7 +9,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 */
 import { PropertiesMixin } from '../../lib/mixins/properties-mixin.js';
 
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { html } from '../../lib/utils/html-tag.js';
 class XPropertiesElement extends PropertiesMixin(HTMLElement) {
   static get properties() {
diff --git a/test/unit/path-effects.html b/test/unit/path-effects.html
index 35aaef3782..cb986c1320 100644
--- a/test/unit/path-effects.html
+++ b/test/unit/path-effects.html
@@ -20,7 +20,7 @@
 <script type="module">
 import '../../polymer-legacy.js';
 import './path-effects-elements.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 // Safari 9 has a horrible bug related to array enumeration after defining
 // a non-enumerable property on it (we do for `.splices`); for now we work
diff --git a/test/unit/polymer-dom-observeNodes.html b/test/unit/polymer-dom-observeNodes.html
index b7cb9f44aa..4850cddd0a 100644
--- a/test/unit/polymer-dom-observeNodes.html
+++ b/test/unit/polymer-dom-observeNodes.html
@@ -23,7 +23,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { dom } from '../../lib/legacy/polymer.dom.js';
 Polymer({
   is:'test-self-observe',
@@ -45,7 +45,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-static'
 });
@@ -58,7 +58,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot'
 });
@@ -71,7 +71,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot1'
 });
@@ -84,7 +84,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot2'
 });
@@ -97,7 +97,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot3'
 });
@@ -110,7 +110,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-raw'
 });
@@ -123,7 +123,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-attr'
 });
@@ -136,7 +136,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-attr1'
 });
@@ -149,7 +149,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-attr2'
 });
@@ -162,7 +162,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-attr3'
 });
@@ -175,7 +175,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is:'test-slot-attr-inside'
 });
diff --git a/test/unit/polymer-dom.html b/test/unit/polymer-dom.html
index 3d3c2b7e57..379f960310 100644
--- a/test/unit/polymer-dom.html
+++ b/test/unit/polymer-dom.html
@@ -23,7 +23,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-slot'
 });
@@ -36,7 +36,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-container-slot'
 });
@@ -49,7 +49,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-event-scoped',
   fireComposed: function() {
@@ -65,7 +65,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-focusable-in-shadow'
 });
diff --git a/test/unit/property-effects-elements.js b/test/unit/property-effects-elements.js
index 77013249ec..41400baa54 100644
--- a/test/unit/property-effects-elements.js
+++ b/test/unit/property-effects-elements.js
@@ -10,7 +10,7 @@ subject to an additional IP rights grant found at http://polymer.github.io/PATEN
 import '../../polymer-legacy.js';
 
 import { StrictBindingParser } from '../../lib/mixins/strict-binding-parser.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { html } from '../../lib/utils/html-tag.js';
 import { PolymerElement } from '../../polymer-element.js';
 import { MutableDataBehavior } from '../../lib/legacy/mutable-data-behavior.js';
diff --git a/test/unit/property-effects.html b/test/unit/property-effects.html
index 8c5da62d3e..4ea25acca2 100644
--- a/test/unit/property-effects.html
+++ b/test/unit/property-effects.html
@@ -25,7 +25,7 @@
 <script type="module">
 import '../../polymer-legacy.js';
 import './property-effects-elements.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { setSanitizeDOMValue, sanitizeDOMValue } from '../../lib/utils/settings.js';
 import { PropertyEffects } from '../../lib/mixins/property-effects.js';
 
diff --git a/test/unit/ready-attached-order.html b/test/unit/ready-attached-order.html
index eda8e41ecf..9815fa31b8 100644
--- a/test/unit/ready-attached-order.html
+++ b/test/unit/ready-attached-order.html
@@ -62,7 +62,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-zot',
   behaviors: [window.readyBehavior]
@@ -76,7 +76,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-bar',
   behaviors: [window.readyBehavior]
@@ -91,7 +91,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-foo',
   behaviors: [window.readyBehavior]
@@ -111,7 +111,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-ready',
   properties: {
@@ -133,7 +133,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-templatized',
   properties: {
diff --git a/test/unit/shady-content.html b/test/unit/shady-content.html
index dd8c0013b5..9494b76243 100644
--- a/test/unit/shady-content.html
+++ b/test/unit/shady-content.html
@@ -33,7 +33,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dist'});
 </script>
 </dom-module>
@@ -44,7 +44,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dist-simple'});
 </script>
 </dom-module>
@@ -53,7 +53,7 @@
   <template><slot></slot></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dist-star'});
 </script>
 </dom-module>
@@ -73,7 +73,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dist-inside-deep-tree'});
 </script>
 </dom-module>
@@ -82,7 +82,7 @@
   <template><span id="static">x-no-dist</span></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-no-dist'});
 </script>
 </dom-module>
@@ -93,7 +93,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-compose-dist'});
 </script>
 </dom-module>
@@ -104,7 +104,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-compose-no-dist'});
 </script>
 </dom-module>
@@ -125,7 +125,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dynamic-content'});
 </script>
 </dom-module>
@@ -142,7 +142,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dynamic-content-wrapped'});
 </script>
 </dom-module>
@@ -157,7 +157,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dynamic-content-redist'});
 </script>
 </dom-module>
@@ -172,7 +172,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dynamic-content-redist-element'});
 </script>
 </dom-module>
@@ -190,7 +190,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-dynamic-content-and-dynamic-no-content'});
 </script>
 </dom-module>
@@ -202,7 +202,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-multi-dist'});
 </script>
 </dom-module>
@@ -221,7 +221,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-compose-lazy-no-dist'});
 </script>
 </dom-module>
@@ -245,7 +245,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-toggle-if',
   properties: {
@@ -266,7 +266,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-repeat',
   properties: {
@@ -289,7 +289,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-repeat2',
   properties: {
@@ -316,7 +316,7 @@
 </script>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 import { flush as flush$0 } from '../../lib/utils/flush.js';
 function createPatchedDocumentFragment() {
   var frag = document.createDocumentFragment();
diff --git a/test/unit/shady-dynamic.html b/test/unit/shady-dynamic.html
index 024657612b..86441305e8 100644
--- a/test/unit/shady-dynamic.html
+++ b/test/unit/shady-dynamic.html
@@ -33,7 +33,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-project'
 });
@@ -46,7 +46,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-reproject'
 });
@@ -59,7 +59,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-rereproject',
   attachedCount: 0,
@@ -76,7 +76,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-test'
 });
@@ -89,7 +89,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-test-no-distribute'
 });
@@ -114,7 +114,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: "x-distribute"
 });
@@ -125,7 +125,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-compose'
 });
@@ -136,7 +136,7 @@
   <template><slot id="x-select3-slot" name="s3"></slot></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-select3'});
 </script>
 </dom-module>
@@ -145,7 +145,7 @@
   <template><x-select3 id="select"><slot id="x-select2-slot" name="s2"></slot></x-select3></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-select2'});
 </script>
 </dom-module>
@@ -154,7 +154,7 @@
   <template><x-select2 id="select"><slot id="x-select1-slot" name="s1"></slot></x-select2></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-select1'});
 </script>
 </dom-module>
@@ -163,7 +163,7 @@
   <template><slot></slot></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-echo'});
 </script>
 </dom-module>
@@ -172,7 +172,7 @@
   <template><div>simple</div></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-simple'});
 </script>
 </dom-module>
@@ -185,7 +185,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-redistribute-a-b'});
 </script>
 </dom-module>
@@ -194,7 +194,7 @@
   <template>Attr1</template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-attr',
   hostAttributes: {
@@ -209,7 +209,7 @@
   <template>Attr2</template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-attr2',
   // TODO(sorvell): cannot put `slot` into properties because it is patched.
@@ -228,7 +228,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-select-attr'});
 </script>
 </dom-module>
@@ -242,7 +242,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-compose-select-attr'});
 </script>
 </dom-module>
@@ -252,7 +252,7 @@
   <template><span>[</span><slot></slot><span>]</span></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-clonate'
 });
@@ -283,7 +283,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-attach3',
   properties: {
@@ -327,7 +327,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-attach2',
   properties: {
@@ -368,7 +368,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-attach1',
   attached: function() {
@@ -384,7 +384,7 @@
   <template><span>[</span><!--comment--><slot></slot></span><span>]</span></slot></template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-commented'});
 </script>
 </dom-module>
@@ -406,7 +406,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'polymer-dom-repeat',
   properties: {
@@ -427,7 +427,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-deep-contains',
   created: function() {
@@ -445,7 +445,7 @@
 <dom-module id="x-wrapped">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-wrapped'
 });
@@ -459,7 +459,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-0',
   hostAttributes: {
@@ -472,7 +472,7 @@
 <dom-module id="x-shadow-host-root-0-0-light-0">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-0-light-0',
   hostAttributes: {
@@ -492,7 +492,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-0-light',
   hostAttributes: {
@@ -508,7 +508,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-1',
   hostAttributes: {
@@ -521,7 +521,7 @@
 <dom-module id="x-shadow-host-root-0-1-light">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-1-light',
   hostAttributes: {
@@ -545,7 +545,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0',
   hostAttributes: {
@@ -558,7 +558,7 @@
 <dom-module id="x-shadow-host-root-0-light">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-0-light',
   hostAttributes: {
@@ -574,7 +574,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-0',
   hostAttributes: {
@@ -587,7 +587,7 @@
 <dom-module id="x-shadow-host-root-1-0-light">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-0-light',
   hostAttributes: {
@@ -603,7 +603,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-1',
   hostAttributes: {
@@ -616,7 +616,7 @@
 <dom-module id="x-shadow-host-root-1-1-light">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-1-light',
   hostAttributes: {
@@ -646,7 +646,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1',
   hostAttributes: {
@@ -659,7 +659,7 @@
 <dom-module id="x-shadow-host-root-1-light-0">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-light-0',
   hostAttributes: {
@@ -675,7 +675,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-1-light',
   hostAttributes: {
@@ -703,7 +703,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root',
   hostAttributes: {
@@ -716,7 +716,7 @@
 <dom-module id="x-shadow-host-root-light">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-shadow-host-root-light',
   hostAttributes: {
@@ -734,7 +734,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-outer'
 });
@@ -744,7 +744,7 @@
 <dom-module id="x-inner">
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-inner',
   attached: function(){
diff --git a/test/unit/shady-events.html b/test/unit/shady-events.html
index b22e0c5f05..24681d1cca 100644
--- a/test/unit/shady-events.html
+++ b/test/unit/shady-events.html
@@ -31,7 +31,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-event-scoped',
   properties: {
@@ -87,7 +87,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-focus',
   properties: {
@@ -123,7 +123,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-a',
   listeners: {
diff --git a/test/unit/shady-unscoped-style.html b/test/unit/shady-unscoped-style.html
index 4fcaf6264c..fb2af89514 100644
--- a/test/unit/shady-unscoped-style.html
+++ b/test/unit/shady-unscoped-style.html
@@ -47,7 +47,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import './shady-unscoped-style-import.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'my-element'
 });
@@ -72,7 +72,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import './shady-unscoped-style-import.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({ is: 'my-element2'});
 </script>
 
@@ -126,4 +126,4 @@
 });
 </script>
 </body>
-</html>
\ No newline at end of file
+</html>
diff --git a/test/unit/shady.html b/test/unit/shady.html
index 51ada8f92c..f3502ab618 100644
--- a/test/unit/shady.html
+++ b/test/unit/shady.html
@@ -19,7 +19,7 @@
 <template></template>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 var template = document.querySelector('template');
 Polymer({
   is: 'x-content-test',
diff --git a/test/unit/styling-cross-scope-apply.html b/test/unit/styling-cross-scope-apply.html
index f9fd9cb94f..d749c4a5e4 100644
--- a/test/unit/styling-cross-scope-apply.html
+++ b/test/unit/styling-cross-scope-apply.html
@@ -39,7 +39,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'story-card'});
 </script>
   </dom-module>
@@ -99,7 +99,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-child-scope'});
 </script>
   </dom-module>
@@ -151,7 +151,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-keyframes',
   properties: {
@@ -280,7 +280,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-scope'});
 </script>
   </dom-module>
@@ -299,7 +299,7 @@
         </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-var-produce-via-consume'
 });
@@ -319,7 +319,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-cache-child'
 });
@@ -341,7 +341,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-cache-host-1'
 });
@@ -363,7 +363,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-cache-host-2'
 });
@@ -386,7 +386,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-no-paren-apply-only'
 });
@@ -404,7 +404,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-redefine-three'});
 </script>
 </dom-module>
@@ -422,7 +422,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-redefine-two'});
 </script>
 </dom-module>
@@ -441,7 +441,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-redefine-one'});
 </script>
 </dom-module>
@@ -485,7 +485,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'order-child'});
 Polymer({is: 'order-parent'});
 Polymer({is: 'order-gp'});
diff --git a/test/unit/styling-cross-scope-unknown-host.html b/test/unit/styling-cross-scope-unknown-host.html
index e4599b0435..9c9cb64b28 100644
--- a/test/unit/styling-cross-scope-unknown-host.html
+++ b/test/unit/styling-cross-scope-unknown-host.html
@@ -56,7 +56,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-foo'
 });
@@ -74,7 +74,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-nest',
 
diff --git a/test/unit/styling-cross-scope-var.html b/test/unit/styling-cross-scope-var.html
index b301d0fe88..1f39756769 100644
--- a/test/unit/styling-cross-scope-var.html
+++ b/test/unit/styling-cross-scope-var.html
@@ -54,7 +54,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-grand-child-scope'});
 </script>
   </dom-module>
@@ -76,7 +76,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-host-property'});
 </script>
   </dom-module>
@@ -87,7 +87,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-host-host-property'});
 </script>
   </dom-module>
@@ -104,7 +104,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-produce-use-property'});
 </script>
   </dom-module>
@@ -142,7 +142,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-child-scope'});
 </script>
   </dom-module>
@@ -163,7 +163,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-overrides'});
 </script>
   </dom-module>
@@ -188,7 +188,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-overrides2'});
 </script>
   </dom-module>
@@ -205,7 +205,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-late'});
 </script>
   </dom-module>
@@ -229,7 +229,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-overrides3'});
 </script>
   </dom-module>
@@ -248,7 +248,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-has-def'});
 </script>
   </dom-module>
@@ -266,7 +266,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-has-if',
   properties: {
@@ -288,7 +288,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-button',
   extends: 'button'
@@ -309,7 +309,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-dynamic'
 });
@@ -361,7 +361,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-keyframes',
   properties: {
@@ -535,7 +535,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-scope'
 });
@@ -556,7 +556,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-inside'
 });
@@ -579,7 +579,7 @@
     </template>
     <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'simple-element'
 });
@@ -599,7 +599,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-variable-override'
 });
@@ -617,7 +617,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-variable-consumer'
 });
@@ -641,7 +641,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-host-variable-consumer'
 });
@@ -660,7 +660,7 @@
         </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-var-produce-via-consume'
 });
@@ -680,7 +680,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-non-media-matching'
 });
@@ -704,7 +704,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-non-media-matching-host'
 });
@@ -731,7 +731,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-update-styles',
   properties: {
diff --git a/test/unit/styling-import.html b/test/unit/styling-import.html
index 59a62d713e..8dc5d648d0 100644
--- a/test/unit/styling-import.html
+++ b/test/unit/styling-import.html
@@ -28,7 +28,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import './styling-import-shared-styles.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({ is: 'x-include-module'});
 </script>
   </dom-module>
@@ -49,7 +49,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import './styling-import-shared-styles.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({ is: 'x-include-import'});
 </script>
   </dom-module>
@@ -67,7 +67,7 @@
     <script type="module">
 import '../../polymer-legacy.js';
 import './styling-import-shared-styles.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-import-order'});
 </script>
   </dom-module>
diff --git a/test/unit/styling-scoped.html b/test/unit/styling-scoped.html
index 5721ff5205..d0f22c756f 100644
--- a/test/unit/styling-scoped.html
+++ b/test/unit/styling-scoped.html
@@ -77,7 +77,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-keyframes',
   properties: {
@@ -99,7 +99,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-gchild'
 });
@@ -119,7 +119,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-child',
   hostAttributes: {
@@ -140,7 +140,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-child2'
 });
@@ -152,7 +152,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-scope-class'
 });
@@ -275,7 +275,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-styled',
 
@@ -315,7 +315,7 @@
 </dom-module>
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 var doc = window.document;
 var dynamic = doc.querySelector('template#dynamic');
 
@@ -342,7 +342,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 var doc = window.document;
 var template = doc.querySelector('template#dynamic-style-template');
 
@@ -378,7 +378,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 var doc = window.document;
 var template = doc.querySelector('template#svg');
 
@@ -409,7 +409,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-specificity'});
 </script>
 </dom-module>
@@ -438,7 +438,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-specificity-parent'});
 </script>
 </dom-module>
@@ -453,7 +453,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-specificity-nested'});
 </script>
 </dom-module>
@@ -497,7 +497,7 @@
 
 <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-overriding'
 });
@@ -528,7 +528,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-attr-selector'});
 </script>
 </dom-module>
@@ -560,7 +560,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-shared1'});
 </script>
 </dom-module>
@@ -572,7 +572,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-shared2'});
 </script>
 </dom-module>
@@ -597,7 +597,7 @@
   </template>
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({is: 'x-slotted'});
 </script>
 </dom-module>
diff --git a/test/unit/sub/resolveurl-elements.js b/test/unit/sub/resolveurl-elements.js
index 3fce1b0838..2cc7410c76 100644
--- a/test/unit/sub/resolveurl-elements.js
+++ b/test/unit/sub/resolveurl-elements.js
@@ -11,7 +11,7 @@ import { html } from '../../../lib/utils/html-tag.js';
 
 import { PolymerElement } from '../../../polymer-element.js';
 import { DomModule } from '../../../lib/elements/dom-module.js';
-import { Polymer } from '../../../lib/utils/boot.js';
+import { Polymer } from '../../../lib/legacy/polymer-fn.js';
 const $_documentContainer = document.createElement('div');
 $_documentContainer.setAttribute('style', 'display: none;');
 $_documentContainer.innerHTML = `<dom-module id="p-r-ap" assetpath="../../assets/"></dom-module>`;
diff --git a/test/unit/sub/x-test.html b/test/unit/sub/x-test.html
index a474d8df33..8cfe535b03 100644
--- a/test/unit/sub/x-test.html
+++ b/test/unit/sub/x-test.html
@@ -3,9 +3,9 @@
     <x-sub id="sub">sub</x-sub>
   </template>
   <script type="module">
-import { Polymer } from '../../../lib/utils/boot.js';
+import { Polymer } from '../../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'x-test'
 })
 </script>
-</dom-module>
\ No newline at end of file
+</dom-module>
diff --git a/test/unit/template-whitespace.html b/test/unit/template-whitespace.html
index 87099d3ab4..7686d0fd50 100644
--- a/test/unit/template-whitespace.html
+++ b/test/unit/template-whitespace.html
@@ -23,7 +23,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'has-whitespace'
 });
@@ -43,7 +43,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'no-whitespace'
 });
@@ -67,7 +67,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'no-whitespace-style'
 });
@@ -88,7 +88,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   is: 'no-whitespace-nested'
 });
@@ -112,7 +112,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   properties: {
     text: {value: 'text'},
@@ -138,7 +138,7 @@
 
   <script type="module">
 import '../../polymer-legacy.js';
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 Polymer({
   properties: {
     items: {
diff --git a/test/unit/templatize-elements.js b/test/unit/templatize-elements.js
index aae6e58c99..e9b7c6d57c 100644
--- a/test/unit/templatize-elements.js
+++ b/test/unit/templatize-elements.js
@@ -7,7 +7,7 @@ The complete set of contributors may be found at http://polymer.github.io/CONTRI
 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
 */
-import { Polymer } from '../../lib/utils/boot.js';
+import { Polymer } from '../../lib/legacy/polymer-fn.js';
 
 import { templatize as templatize$0 } from '../../lib/utils/templatize.js';
 import { Templatizer } from '../../lib/legacy/templatizer-behavior.js';
@@ -174,7 +174,7 @@ Polymer({
       <template>
         <x-child on-tap="handleTap" id="childC" outer-prop="{{outerProp}}" outer-obj="{{outerObj}}" outer-obj-prop="{{outerObj.prop}}" prop="{{prop}}" obj="{{obj}}" obj-prop="{{obj.prop}}" conflict="{{outerInnerConflict.prop}}" computed-from-literal="{{computeFromLiteral(33, prop)}}"></x-child>
       </template>
-    
+
 
   </x-templatize-behavior>
 `,