diff --git a/lib/Alchemy/Phrasea/SearchEngine/Elastic/Indexer/Record/Hydrator/MetadataHydrator.php b/lib/Alchemy/Phrasea/SearchEngine/Elastic/Indexer/Record/Hydrator/MetadataHydrator.php
index e3b94e626d..34fe519718 100644
--- a/lib/Alchemy/Phrasea/SearchEngine/Elastic/Indexer/Record/Hydrator/MetadataHydrator.php
+++ b/lib/Alchemy/Phrasea/SearchEngine/Elastic/Indexer/Record/Hydrator/MetadataHydrator.php
@@ -61,7 +61,7 @@ SQL;
             $value = $metadata['value'];
 
             // Do not keep empty values
-            if (empty($key) || empty($value)) {
+            if ($key === '' || $value === '') {
                 continue;
             }