diff --git a/src/Plugin/monitoring/SensorPlugin/ContentEntityAggregatorSensorPlugin.php b/src/Plugin/monitoring/SensorPlugin/ContentEntityAggregatorSensorPlugin.php
index 3edc634..6bae2ca 100644
--- a/src/Plugin/monitoring/SensorPlugin/ContentEntityAggregatorSensorPlugin.php
+++ b/src/Plugin/monitoring/SensorPlugin/ContentEntityAggregatorSensorPlugin.php
@@ -244,7 +244,7 @@ class ContentEntityAggregatorSensorPlugin extends DatabaseAggregatorSensorPlugin
             break;
 
           default:
-            if ($entity->hasField($field)) {
+            if (is_subclass_of($entity, '\Drupal\Core\Entity\FieldableEntityInterface', TRUE) && $entity->hasField($field)) {
               $property = $entity->getFieldDefinition($field)->getFieldStorageDefinition()->getMainPropertyName();
               $value = $entity->$field->view(['label' => 'hidden']);
               $row[] = $value ? \Drupal::service('renderer')->renderPlain($value) : $entity->$field->$property;
@@ -302,7 +302,7 @@ class ContentEntityAggregatorSensorPlugin extends DatabaseAggregatorSensorPlugin
     $options = [];
     foreach ($entity_types as $id => $label) {
       $class = $this->entityManager->getDefinition($id)->getClass();
-      if (is_subclass_of($class, '\Drupal\Core\Entity\FieldableEntityInterface', TRUE)) {
+      if (is_subclass_of($class, '\Drupal\Core\Entity\ContentEntityInterface', TRUE)) {
         $options[$id] = $label;
       };
     }