diff --git a/src/panels/lovelace/hui-view.js b/src/panels/lovelace/hui-view.js
index 9dad500ad2..cd0534bcc8 100644
--- a/src/panels/lovelace/hui-view.js
+++ b/src/panels/lovelace/hui-view.js
@@ -110,6 +110,7 @@ class HUIView extends PolymerElement {
   constructor() {
     super();
     this._elements = [];
+    this._whenDefined = {};
   }
 
   _getElements(cards) {
@@ -127,6 +128,10 @@ class HUIView extends PolymerElement {
           error = `Unknown card type encountered: "${cardConfig.type}".`;
         } else if (!customElements.get(tag)) {
           error = `Custom element doesn't exist: "${tag}".`;
+          if (!(tag in this._whenDefined)) {
+            this._whenDefined[tag] = customElements.whenDefined(tag)
+              .then(() => this._configChanged());
+          }
         }
       }
       if (error) {