diff --git a/include/config_default.inc.php b/include/config_default.inc.php
index 4d03c1ee6..cdc2c823a 100644
--- a/include/config_default.inc.php
+++ b/include/config_default.inc.php
@@ -850,6 +850,12 @@ $conf['batch_manager_images_per_page_unit'] = 5;
 // how many missing md5sum should Piwigo compute at once.
 $conf['checksum_compute_blocksize'] = 50;
 
+// quicksearch engine: include all photos from sub-albums of any matching
+// album. For example, if search is "bear", then we display photos from
+// "bear/grizzly". When value changed, delete database cache files in
+// _data/cache directory
+$conf['quick_search_include_sub_albums'] = false;
+
 // +-----------------------------------------------------------------------+
 // |                                 log                                   |
 // +-----------------------------------------------------------------------+
diff --git a/include/functions_search.inc.php b/include/functions_search.inc.php
index 379bb93e2..53700b4bc 100644
--- a/include/functions_search.inc.php
+++ b/include/functions_search.inc.php
@@ -1119,7 +1119,7 @@ SELECT image_id FROM '.IMAGE_TAG_TABLE.'
 
 function qsearch_get_categories(QExpression $expr, QResults $qsr)
 {
-  global $user;
+  global $user, $conf;
 
   $token_cat_ids = $qsr->cat_iids = array_fill(0, count($expr->stokens), array() );
   $all_cats = array();
@@ -1171,6 +1171,18 @@ SELECT
 
     if (!empty($cat_ids))
     {
+      if ($conf['quick_search_include_sub_albums'])
+      {
+        $query = '
+SELECT
+    id
+  FROM '.CATEGORIES_TABLE.'
+    INNER JOIN '.USER_CACHE_CATEGORIES_TABLE.' ON id = cat_id and user_id = '.$user['id'].'
+  WHERE id IN ('.implode(',', get_subcat_ids($cat_ids)) .')
+;';
+        $cat_ids = query2array($query, null, 'id');
+      }
+
       $query = '
 SELECT image_id FROM '.IMAGE_CATEGORY_TABLE.'
   WHERE category_id IN ('.implode(',',$cat_ids).')