diff --git a/selfdrive/car/gm/interface.py b/selfdrive/car/gm/interface.py
index bdb42f97e2..7eb952f14c 100755
--- a/selfdrive/car/gm/interface.py
+++ b/selfdrive/car/gm/interface.py
@@ -70,6 +70,7 @@ class CarInterface(CarInterfaceBase):
     ret.lateralTuning.pid.kpV, ret.lateralTuning.pid.kiV = [[0.2], [0.00]]
     ret.lateralTuning.pid.kf = 0.00004   # full torque for 20 deg at 80mph means 0.00007818594
     ret.steerActuatorDelay = 0.1  # Default delay, not measured yet
+    ret.longitudinalActuatorDelayUpperBound = 0.5  # large delay to initially start braking
 
     ret.longitudinalTuning.kpBP = [5., 35.]
     ret.longitudinalTuning.kpV = [2.4, 1.5]