diff --git a/polygerrit-ui/app/elements/gr-app-element.html b/polygerrit-ui/app/elements/gr-app-element.html
index af4d799..20f5996 100644
--- a/polygerrit-ui/app/elements/gr-app-element.html
+++ b/polygerrit-ui/app/elements/gr-app-element.html
@@ -72,10 +72,6 @@
         padding: 0 var(--default-horizontal-margin);
         border-bottom: 1px solid var(--border-color);
       }
-      gr-main-header.shadow {
-        /* Make it obvious for shadow dom testing */
-        border-bottom: 1px solid pink;
-      }
       footer {
         background-color: var(--footer-background-color);
         border-top: 1px solid var(--border-color);
@@ -125,7 +121,6 @@
       <gr-main-header
           id="mainHeader"
           search-query="{{params.query}}"
-          class$="[[_computeShadowClass(_isShadowDom)]]"
           on-mobile-search="_mobileSearchToggle">
       </gr-main-header>
     </gr-fixed-panel>
@@ -191,7 +186,7 @@
         <div class="errorMoreInfo">[[_lastError.moreInfo]]</div>
       </div>
     </main>
-    <footer r="contentinfo" class$="[[_computeShadowClass(_isShadowDom)]]">
+    <footer r="contentinfo">
       <div>
         Powered by <a href="https://www.gerritcodereview.com/" rel="noopener"
         target="_blank">Gerrit Code Review</a>
diff --git a/polygerrit-ui/app/elements/gr-app-element.js b/polygerrit-ui/app/elements/gr-app-element.js
index 3f41e5b..af69af8 100644
--- a/polygerrit-ui/app/elements/gr-app-element.js
+++ b/polygerrit-ui/app/elements/gr-app-element.js
@@ -73,7 +73,6 @@
       _lastError: Object,
       _lastSearchPage: String,
       _path: String,
-      _isShadowDom: Boolean,
       _pluginScreenName: {
         type: String,
         computed: '_computePluginScreenName(params)',
@@ -123,7 +122,6 @@
 
     ready() {
       this.$.reporting.appStarted(document.visibilityState === 'hidden');
-      this._isShadowDom = Polymer.Settings.useShadow;
       this.$.router.start();
 
       this.$.restAPI.getAccount().then(account => {
@@ -403,10 +401,6 @@
       this.$.registrationOverlay.close();
     },
 
-    _computeShadowClass(isShadowDom) {
-      return isShadowDom ? 'shadow' : '';
-    },
-
     _goToOpenedChanges() {
       Gerrit.Nav.navigateToStatusSearch('open');
     },