diff --git a/rl_hm/data_fetcher/cluster.py b/rl_hm/data_fetcher/cluster.py
index 2ce8736d1de763d4d76b55971d0d9136f46dc9e5..09f3ca2c7eb40edde1aa06e0ed2f85b35db8f926 100644
--- a/rl_hm/data_fetcher/cluster.py
+++ b/rl_hm/data_fetcher/cluster.py
@@ -18,7 +18,7 @@ PRETTY_GPU_MODELS: dict[str, str] = {
 }
 
 
-USERNAMES = [
+USERNAMES: list[str] = [
     'aballou',
     'galepage',
     'aauterna',