diff --git a/selfdrive/controls/lib/pathplanner.py b/selfdrive/controls/lib/pathplanner.py
index 48ae4baca0..40e6c38002 100644
--- a/selfdrive/controls/lib/pathplanner.py
+++ b/selfdrive/controls/lib/pathplanner.py
@@ -87,7 +87,12 @@ class PathPlanner():
 
     # Run MPC
     self.angle_steers_des_prev = self.angle_steers_des_mpc
-    VM.update_params(sm['liveParameters'].stiffnessFactor, sm['liveParameters'].steerRatio)
+
+    # Update vehicle model
+    x = max(sm['liveParameters'].stiffnessFactor, 0.1)
+    sr = max(sm['liveParameters'].steerRatio, 0.1)
+    VM.update_params(x, sr)
+
     curvature_factor = VM.curvature_factor(v_ego)
 
     self.LP.parse_model(sm['model'])