diff --git a/data_safe_haven/config/backend_settings.py b/data_safe_haven/config/backend_settings.py
index 79e00cd476..ebc20e455e 100644
--- a/data_safe_haven/config/backend_settings.py
+++ b/data_safe_haven/config/backend_settings.py
@@ -35,7 +35,7 @@ def __init__(
 
         # Load previous backend settings (if any)
         self.config_directory = pathlib.Path(
-            appdirs.user_config_dir("data_safe_haven")
+            appdirs.user_config_dir(appname="data_safe_haven")
         ).resolve()
         self.config_file_path = self.config_directory / "config.yaml"
         self.read()