diff --git a/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
index 749aae0..f414e2c 100644
--- a/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
+++ b/modules/ctools_block/src/Plugin/Deriver/EntityFieldDeriver.php
@@ -21,14 +21,22 @@ class EntityFieldDeriver extends EntityDeriverBase {
   public function getDerivativeDefinitions($base_plugin_definition) {
     $entity_type_labels = $this->entityManager->getEntityTypeLabels();
     foreach ($this->entityManager->getFieldMap() as $entity_type_id => $entity_field_map) {
-      foreach ($this->entityManager->getFieldStorageDefinitions($entity_type_id) as $field_definition) {
-        $field_name = $field_definition->getName();
+      foreach ($this->entityManager->getFieldStorageDefinitions($entity_type_id) as $field_storage_definition) {
+        $field_name = $field_storage_definition->getName();
+
+        // The blocks are based on fields. However, we are looping through field
+        // storages for which no fields may exist. If that is the case, skip
+        // this field storage.
+        if (!isset($entity_field_map[$field_name])) {
+          continue;
+        }
+
         $field_info = $entity_field_map[$field_name];
         $derivative_id = $entity_type_id . ":" . $field_name;
 
         // Get the admin label for both base and configurable fields.
-        if ($field_definition->isBaseField()) {
-          $admin_label = $field_definition->getLabel();
+        if ($field_storage_definition->isBaseField()) {
+          $admin_label = $field_storage_definition->getLabel();
         }
         else {
           // We take the field label used on the first bundle.