diff --git a/pymonetdb/mapi.py b/pymonetdb/mapi.py
index 61124bad..a527ecce 100644
--- a/pymonetdb/mapi.py
+++ b/pymonetdb/mapi.py
@@ -603,7 +603,7 @@ def _challenge_response(self, challenge: str):  # noqa: C901
                 if not application_name and sys.argv:
                     application_name = os.path.basename(sys.argv[0])
                 self.clientinfo = dict(
-                    ClientHostName=platform.node() or None,
+                    ClientHostname=platform.node() or None,
                     ApplicationName=application_name or None,
                     ClientLibrary=f"pymonetdb {__version__}",
                     ClientRemark=self.target.client_remark or None,