diff --git a/tests/features/joinup_search/search.feature b/tests/features/joinup_search/search.feature
index 4efa2b84fa..a3994a11a4 100644
--- a/tests/features/joinup_search/search.feature
+++ b/tests/features/joinup_search/search.feature
@@ -199,17 +199,17 @@ Feature: Global search
       | title       | Bird outposts in the wild            |
       | description | Exotic wings and where to find them. |
       | state       | validated                            |
-    And collection:
-      | title       | Ornithology: the study of birds     |
-      | description | Ornithology is a branch of zoology. |
-      | state       | validated                           |
-      | affiliates  | Bird outposts in the wild           |
+    And collections:
+      | title                           | description                         | state     | affiliates                |
+      | Ornithology: the study of birds | Ornithology is a branch of zoology. | validated | Bird outposts in the wild |
+      | Husky Flying Xylophone          | A strange instrument.               | validated |                           |
     And custom_page content:
       | title           | body                                  | collection                      |
       | Disturbed birds | Flocks of trained pigeons flying off. | Ornithology: the study of birds |
     And news content:
-      | title                    | body                   | collection                      | state     |
-      | Chickens are small birds | Domesticated in India. | Ornithology: the study of birds | validated |
+      | title                               | body                            | collection                      | state     |
+      | Chickens are small birds            | Birds domesticated in India.    | Ornithology: the study of birds | validated |
+      | Found a xylophone from 1600 in Asia | Oldest instrument of this type. | Husky Flying Xylophone          | validated |
     And event content:
       | title         | body                   | collection                      | state     |
       | Bird spotting | Roosters crow at dawn. | Ornithology: the study of birds | validated |
diff --git a/web/modules/custom/joinup_search/joinup_search.module b/web/modules/custom/joinup_search/joinup_search.module
index 20db62d750..314af525ea 100644
--- a/web/modules/custom/joinup_search/joinup_search.module
+++ b/web/modules/custom/joinup_search/joinup_search.module
@@ -165,12 +165,15 @@ function joinup_search_search_api_solr_field_mapping_alter(IndexInterface $index
  * Implements hook_search_api_solr_query_alter().
  */
 function joinup_search_search_api_solr_query_alter(SolariumQueryInterface $solarium_query, QueryInterface $query): void {
-  if (
-    !$solarium_query instanceof Query
-  ) {
+  if (!$solarium_query instanceof Query) {
     return;
   }
 
+  // Keep the edismax parser to allow document boosting to work properly.
+  // @todo remove when document boosting is reimplemented by search_api_solr
+  // @see https://webgate.ec.europa.eu/CITnet/jira/browse/ISAICP-4907
+  $solarium_query->addParam('defType', 'edismax');
+
   /** @var \Drupal\search_api_field\Plugin\Field\FieldType\SearchItem $item */
   if (!$item = $query->getOption('search_api_field item')) {
     return;