diff --git a/lib/Alchemy/Phrasea/Controller/Api/V1Controller.php b/lib/Alchemy/Phrasea/Controller/Api/V1Controller.php
index 1eb2810372..9fbcdb91cb 100644
--- a/lib/Alchemy/Phrasea/Controller/Api/V1Controller.php
+++ b/lib/Alchemy/Phrasea/Controller/Api/V1Controller.php
@@ -2588,8 +2588,18 @@ class V1Controller extends Controller
         foreach ($recordsData as $data) {
             $records[] = $this->addOrDelStoryRecord($story, $data, $action);
             if($action === 'ADD' && !$cover_set && isset($data->{'use_as_cover'}) && $data->{'use_as_cover'} === true) {
+                $coverSource = [];
+
+                if (isset($data->{'thumbnail_cover_source'})) {
+                    $coverSource['thumbnail_cover_source'] = $data->{'thumbnail_cover_source'};
+                }
+
+                if (isset($data->{'preview_cover_source'})) {
+                    $coverSource['preview_cover_source'] = $data->{'preview_cover_source'};
+                }
+
                 // because we can try many records as cover source, we let it fail
-                $cover_set = ($this->setStoryCover($story, $data->{'record_id'}, true) !== false);
+                $cover_set = ($this->setStoryCover($story, $data->{'record_id'}, true, $coverSource) !== false);
             }
         }
 
@@ -2643,14 +2653,26 @@ class V1Controller extends Controller
 
         $story = new \record_adapter($this->app, $databox_id, $story_id);
 
+        $coverSource = [];
+
+        if (isset($data->{'thumbnail_cover_source'})) {
+            $coverSource['thumbnail_cover_source'] = $data->{'thumbnail_cover_source'};
+        }
+
+        if (isset($data->{'preview_cover_source'})) {
+            $coverSource['preview_cover_source'] = $data->{'preview_cover_source'};
+        }
+
         // we do NOT let "setStoryCover()" fail : pass false as last arg
-        $record_key = $this->setStoryCover($story, $data->{'record_id'}, false);
+        $record_key = $this->setStoryCover($story, $data->{'record_id'}, false, $coverSource);
 
         return Result::create($request, array($record_key))->createResponse();
     }
 
-    protected function setStoryCover(\record_adapter $story, $record_id, $can_fail=false)
+    protected function setStoryCover(\record_adapter $story, $record_id, $can_fail=false, $coverSource = [])
     {
+        $coverSource = array_merge(['thumbnail_cover_source' => 'thumbnail', 'preview_cover_source' => 'preview'], $coverSource);
+
         try {
             $record = new \record_adapter($this->app, $story->getDataboxId(), $record_id);
         } catch (\Exception_Record_AdapterNotFound $e) {
@@ -2671,9 +2693,12 @@ class V1Controller extends Controller
         }
 
         foreach ($record->get_subdefs() as $name => $value) {
-            if (!in_array($name, array('thumbnail', 'preview'))) {
+            if (!($key = array_search($name, $coverSource))) {
                 continue;
             }
+
+            $name = ($key == 'thumbnail_cover_source') ? 'thumbnail': 'preview';
+
             $media = $this->app->getMediaFromUri($value->getRealPath());
             $this->getSubdefSubstituer()->substituteSubdef($story, $name, $media);  // name = thumbnail | preview
             $this->getDataboxLogger($story->getDatabox())->log(