diff --git a/lib/elastic/transport/meta_header.rb b/lib/elastic/transport/meta_header.rb
index bec96ab..8dd48d6 100644
--- a/lib/elastic/transport/meta_header.rb
+++ b/lib/elastic/transport/meta_header.rb
@@ -42,7 +42,7 @@ def meta_header_service_version
         if enterprise_search?
           Elastic::ENTERPRISE_SERVICE_VERSION
         elsif serverless?
-          Elastic::ES_SERVERLESS_SERVICE_VERSION
+          Elastic::ES_SERVERLESS_SERVICE_VERSION || Elastic::ELASTICSEARCH_SERVICE_VERSION
         elsif elasticsearch?
           Elastic::ELASTICSEARCH_SERVICE_VERSION
         elsif defined?(Elasticsearch::VERSION)