diff --git a/selfdrive/car/hyundai/carstate.py b/selfdrive/car/hyundai/carstate.py
index a2940a3b91..2173565d06 100644
--- a/selfdrive/car/hyundai/carstate.py
+++ b/selfdrive/car/hyundai/carstate.py
@@ -27,8 +27,8 @@ class CarState(CarStateBase):
     super().__init__(CP)
     can_define = CANDefine(DBC[CP.carFingerprint]["pt"])
 
-    self.cruise_buttons = deque([Buttons.NONE] * PREV_BUTTON_SAMPLES, maxlen=PREV_BUTTON_SAMPLES)
-    self.main_buttons = deque([Buttons.NONE] * PREV_BUTTON_SAMPLES, maxlen=PREV_BUTTON_SAMPLES)
+    self.cruise_buttons: deque = deque([Buttons.NONE] * PREV_BUTTON_SAMPLES, maxlen=PREV_BUTTON_SAMPLES)
+    self.main_buttons: deque = deque([Buttons.NONE] * PREV_BUTTON_SAMPLES, maxlen=PREV_BUTTON_SAMPLES)
 
     self.gear_msg_canfd = "GEAR_ALT" if CP.flags & HyundaiFlags.CANFD_ALT_GEARS else \
                           "GEAR_ALT_2" if CP.flags & HyundaiFlags.CANFD_ALT_GEARS_2 else \