diff --git a/selfdrive/car/gm/carstate.py b/selfdrive/car/gm/carstate.py
index 9fb756f2c9..21b5779ed8 100644
--- a/selfdrive/car/gm/carstate.py
+++ b/selfdrive/car/gm/carstate.py
@@ -44,7 +44,7 @@ class CarState(CarStateBase):
     ret.vEgoRaw = mean([ret.wheelSpeeds.fl, ret.wheelSpeeds.fr, ret.wheelSpeeds.rl, ret.wheelSpeeds.rr])
     ret.vEgo, ret.aEgo = self.update_speed_kf(ret.vEgoRaw)
     # sample rear wheel speeds, standstill=True if ECM allows engagement with brake
-    ret.standstill = ret.wheelSpeeds.rl <= STANDSTILL_THRESHOLD and ret.wheelSpeeds.rr <= STANDSTILL_THRESHOLD
+    ret.standstill = abs(ret.wheelSpeeds.rl) <= STANDSTILL_THRESHOLD and abs(ret.wheelSpeeds.rr) <= STANDSTILL_THRESHOLD
 
     if pt_cp.vl["ECMPRDNL2"]["ManualMode"] == 1:
       ret.gearShifter = self.parse_gear_shifter("T")