diff --git a/tests/functional/search/mysql_test.php b/tests/functional/search/mysql_test.php
index a97b12e905..f7e6cbf5f1 100644
--- a/tests/functional/search/mysql_test.php
+++ b/tests/functional/search/mysql_test.php
@@ -20,4 +20,17 @@ class phpbb_functional_search_mysql_test extends phpbb_functional_search_base
 {
 	protected $search_backend = '\phpbb\search\fulltext_mysql';
 
+	protected function create_search_index($backend = null)
+	{
+		parent::create_search_index($backend);
+
+		// Try optimizing posts table after creating search index.
+		// Some versions of MariaDB might not return any results in the search
+		// until the table has been optimized or the index deleted and re-created.
+		$db = $this->get_db();
+		$db->sql_return_on_error(true);
+		$sql = 'OPTIMIZE TABLE ' . POSTS_TABLE;
+		$db->sql_query($sql);
+		$db->sql_return_on_error(false);
+	}
 }