diff --git a/src/panels/lovelace/cards/hui-glance-card.js b/src/panels/lovelace/cards/hui-glance-card.js
index db8bf7ebf5..c4796e4655 100644
--- a/src/panels/lovelace/cards/hui-glance-card.js
+++ b/src/panels/lovelace/cards/hui-glance-card.js
@@ -86,8 +86,6 @@ class HuiGlanceCard extends LocalizeMixin(EventsMixin(PolymerElement)) {
   }
 
   _computeEntities(config) {
-    const entities = computeConfigEntities(config);
-
     if (!validateEntitiesConfig(config)) {
       const error = 'Error in card configuration.';
       this._error = createErrorCardConfig(error, config);
@@ -95,7 +93,7 @@ class HuiGlanceCard extends LocalizeMixin(EventsMixin(PolymerElement)) {
     }
 
     this._error = null;
-    return entities;
+    return computeConfigEntities(config);
   }
 
   _showEntity(item, states) {
diff --git a/src/panels/lovelace/common/validate-entities-config.js b/src/panels/lovelace/common/validate-entities-config.js
index c005a5b276..4fe36aa438 100644
--- a/src/panels/lovelace/common/validate-entities-config.js
+++ b/src/panels/lovelace/common/validate-entities-config.js
@@ -13,6 +13,11 @@ export default function validateEntitiesConfig(config, additionalKeys = []) {
     return false;
   }
 
-  return entities.every(entity => entity && typeof entity === 'object' && !Array.isArray(entity) &&
-    'entity' in entity && validEntityId(entity.entity) && additionalKeys.every(key => key in entity));
+  return entities.every(entity => {
+    if (typeof entity === 'string') {
+      return validEntityId(entity) && !additionalKeys.length;
+    }
+    return entity && typeof entity === 'object' && !Array.isArray(entity) &&
+      'entity' in entity && validEntityId(entity.entity) && additionalKeys.every(key => key in entity)
+  });
 }