diff --git a/radicale/__init__.py b/radicale/__init__.py
index e513a58..692e633 100644
--- a/radicale/__init__.py
+++ b/radicale/__init__.py
@@ -90,7 +90,7 @@ class HTTPSServer(HTTPServer):
             try:
                 open(filename, "r").close()
             except IOError as exception:
-                log.LOGGER.warn(
+                log.LOGGER.warning(
                     "Error while reading SSL %s %r: %s" % (
                         name, filename, exception))