diff --git a/src/EntityReferenceRevisionsOrphanPurger.php b/src/EntityReferenceRevisionsOrphanPurger.php
index 88c620c..ac7d2f4 100644
--- a/src/EntityReferenceRevisionsOrphanPurger.php
+++ b/src/EntityReferenceRevisionsOrphanPurger.php
@@ -220,6 +220,13 @@ class EntityReferenceRevisionsOrphanPurger {
     if (!$this->entityTypeManager->hasDefinition($parent_type)) {
       return FALSE;
     }
+    // Check if the parent field is valid.
+    if (!($parent_field_config = $this->entityTypeManager->getStorage('field_storage_config')->load("$parent_type.$parent_field_name"))) {
+      return FALSE;
+    }
+    if ($parent_field_config->get('type') != 'entity_reference_revisions') {
+      return FALSE;
+    }
     // Check if the revision is used in any revision of the parent, if that
     // entity type supports revisions.
     $query = $this->entityTypeManager->getStorage($parent_type)->getQuery()