diff --git a/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
index 749aae0..0d8f5ad 100644
--- a/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
+++ b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
@@ -23,6 +23,11 @@ class EntityFieldDeriver extends EntityDeriverBase {
     foreach ($this->entityManager->getFieldMap() as $entity_type_id => $entity_field_map) {
       foreach ($this->entityManager->getFieldStorageDefinitions($entity_type_id) as $field_definition) {
         $field_name = $field_definition->getName();
+
+        if (!isset($entity_field_map[$field_name])) {
+          continue;
+        }
+
         $field_info = $entity_field_map[$field_name];
         $derivative_id = $entity_type_id . ":" . $field_name;