diff --git a/ptd_client_server/lib/time_sync.py b/ptd_client_server/lib/time_sync.py
index fe7bb620..0331cba3 100644
--- a/ptd_client_server/lib/time_sync.py
+++ b/ptd_client_server/lib/time_sync.py
@@ -24,7 +24,7 @@
 from ptd_client_server.lib.external import ntplib  # type: ignore
 
 
-CRITICAL_DIFFERENCE_TIME_MS = 200
+CRITICAL_DIFFERENCE_TIME_MS = 400
 
 
 def get_ntp_response(server: str) -> Any: