diff --git a/src/Plugin/search_api/processor/FilesFieldsProcessorPlugin.php b/src/Plugin/search_api/processor/FilesFieldsProcessorPlugin.php
index 80f3189..077e2a7 100644
--- a/src/Plugin/search_api/processor/FilesFieldsProcessorPlugin.php
+++ b/src/Plugin/search_api/processor/FilesFieldsProcessorPlugin.php
@@ -111,11 +111,19 @@ class FilesFieldsProcessorPlugin extends ProcessorPluginBase {
             if ($entity->hasField($field_name)) {
               $filefield_values = $entity->get($field_name)->getValue();
 
-              $all_fids = array();
-              foreach ($filefield_values as $filefield_value) {
-                $all_fids[] = $filefield_value['target_id'];
+              if ($field_name != 'fid') {
+                $all_fids = array();
+                foreach ($filefield_values as $filefield_value) {
+                  $all_fids[] = $filefield_value['target_id'];
+                }
+                $fids = $this->limitToAllowedNumber($all_fids);
+              }
+              else {
+                // There's only one file in a file entity.
+                $fid = $filefield_values[0]['value'];
+                $fids = array($fid => $fid);
               }
-              $fids = $this->limitToAllowedNumber($all_fids);
+
               // Retrieve the files.
               $files = \Drupal::entityTypeManager()
                 ->getStorage('file')
@@ -294,6 +302,12 @@ class FilesFieldsProcessorPlugin extends ProcessorPluginBase {
             $file_fields[$property->get('field_name')] = $property->get('label');
           }
         }
+        // Check if it is a file entity.
+        if ($property->getTargetEntityTypeId() == 'file') {
+          if ($property->getName() == 'fid') {
+            $file_fields[$property->getName()] = 'File entity';
+          }
+        }
       }
     }
     return $file_fields;