diff --git a/lib/logitech_receiver/hidpp20.py b/lib/logitech_receiver/hidpp20.py
index 05295846..92d09dec 100644
--- a/lib/logitech_receiver/hidpp20.py
+++ b/lib/logitech_receiver/hidpp20.py
@@ -118,6 +118,7 @@ class MappingFlag(Flag):
     UNUSED_4000 = 0x4000
     UNUSED_1000 = 0x1000
     RAW_WHEEL = 0x400
+    UNKNOWN_200 = 0x200  # seen on a Wireless Mouse M510 WPID 4004
     ANALYTICS_KEY_EVENTS_REPORTING = 0x100
     FORCE_RAW_XY_DIVERTED = 0x40
     RAW_XY_DIVERTED = 0x10