diff --git a/panels/config/ha-entity-config.html b/panels/config/ha-entity-config.html
index 9997b3e913..2ed361f1cf 100644
--- a/panels/config/ha-entity-config.html
+++ b/panels/config/ha-entity-config.html
@@ -24,6 +24,10 @@
         @apply(--layout-horizontal);
         @apply(--layout-justified);
       }
+
+      dom-if {
+        display: none;
+      }
     </style>
     <paper-card>
       <div class='card-content'>
diff --git a/src/components/ha-sidebar.html b/src/components/ha-sidebar.html
index edb24d593c..195c2aa1ff 100644
--- a/src/components/ha-sidebar.html
+++ b/src/components/ha-sidebar.html
@@ -93,6 +93,10 @@
         padding: 0 8px;
         opacity: var(--dark-secondary-opacity);
       }
+
+      dom-if {
+        display: none;
+      }
     </style>
 
     <app-toolbar>
diff --git a/src/state-summary/state-card-script.html b/src/state-summary/state-card-script.html
index b28b1263ff..f6a7023d36 100644
--- a/src/state-summary/state-card-script.html
+++ b/src/state-summary/state-card-script.html
@@ -22,6 +22,10 @@
       ha-entity-toggle {
         margin-left: 16px;
       }
+
+      dom-if {
+        display: none;
+      }
     </style>
 
     <div class='horizontal justified layout'>
diff --git a/src/util/hass-util.html b/src/util/hass-util.html
index ddcd320645..f9fe871589 100644
--- a/src/util/hass-util.html
+++ b/src/util/hass-util.html
@@ -106,9 +106,15 @@ window.hassUtil.dynamicContentUpdater = function (root, newElementTag, attribute
     customEl = document.createElement(newElementTag);
   }
 
-  Object.keys(attributes).forEach(function (key) {
-    customEl[key] = attributes[key];
-  });
+  if (customEl.setProperties) {
+    customEl.setProperties(attributes);
+  } else {
+    // If custom element definition wasn't loaded yet - setProperties would be
+    // missing, but no harm in setting attributes one-by-one then.
+    Object.keys(attributes).forEach((key) => {
+      customEl[key] = attributes[key];
+    });
+  }
 
   if (customEl.parentNode === null) {
     rootEl.appendChild(customEl);