diff --git a/src/hidpp20.c b/src/hidpp20.c
index 273d7dc5..7f5ce5c5 100644
--- a/src/hidpp20.c
+++ b/src/hidpp20.c
@@ -543,7 +543,9 @@ static const struct hidpp20_1b04_mapping hidpp20_1b04_physical_mapping[] =
 	{ 56, "Left Click"		, RATBAG_BUTTON_TYPE_LEFT},
 	{ 57, "Right Click"		, RATBAG_BUTTON_TYPE_RIGHT},
 	{ 58, "Middle Click"		, RATBAG_BUTTON_TYPE_MIDDLE},
+	{ 59, "Wheel Side Click Left"	, RATBAG_BUTTON_TYPE_UNKNOWN},
 	{ 60, "Back Click"		, RATBAG_BUTTON_TYPE_SIDE},
+	{ 61, "Wheel Side Click Right"	, RATBAG_BUTTON_TYPE_UNKNOWN},
 	{ 62, "Forward Click"		, RATBAG_BUTTON_TYPE_EXTRA},
 	{ 156, "Gesture Button"		, RATBAG_BUTTON_TYPE_UNKNOWN},
 	{ 157, "SmartShift"		, RATBAG_BUTTON_TYPE_UNKNOWN},