diff --git a/src/frostfs_testlib/storage/cluster.py b/src/frostfs_testlib/storage/cluster.py
index 3ec4922..b67e34d 100644
--- a/src/frostfs_testlib/storage/cluster.py
+++ b/src/frostfs_testlib/storage/cluster.py
@@ -91,10 +91,10 @@ class ClusterNode:
         config_str = yaml.dump(new_config)
         shell.exec(f"echo '{config_str}' | sudo tee {config_file_path}")
 
-    def config(self, service_type: ServiceClass) -> ServiceConfigurationYml:
+    def config(self, service_type: type[ServiceClass]) -> ServiceConfigurationYml:
         return self.service(service_type).config
 
-    def service(self, service_type: ServiceClass) -> ServiceClass:
+    def service(self, service_type: type[ServiceClass]) -> ServiceClass:
         """
         Get a service cluster node of specified type.