diff --git a/artiq/master/worker_impl.py b/artiq/master/worker_impl.py
index 784e4297a..cd575d214 100644
--- a/artiq/master/worker_impl.py
+++ b/artiq/master/worker_impl.py
@@ -196,7 +196,7 @@ def setup_diagnostics(experiment_file, repository_path):
             message = message.replace(repository_path, "<repository>")
 
         if diagnostic.level == "warning":
-            logging.warn(message)
+            logging.warning(message)
         else:
             logging.error(message)