diff --git a/selfdrive/controls/lib/longitudinal_mpc_lib/long_mpc.py b/selfdrive/controls/lib/longitudinal_mpc_lib/long_mpc.py
index 577651f8d4..33b996a59c 100644
--- a/selfdrive/controls/lib/longitudinal_mpc_lib/long_mpc.py
+++ b/selfdrive/controls/lib/longitudinal_mpc_lib/long_mpc.py
@@ -298,8 +298,9 @@ class LongitudinalMpc():
     self.cruise_min_a = min_a
     self.cruise_max_a = max_a
 
-  def update(self, carstate, radarstate, v_cruise):
+  def update(self, carstate, radarstate, v_cruise, prev_accel_constraint=False):
     v_ego = self.x0[1]
+    a_ego = self.x0[2]
     self.status = radarstate.leadOne.status or radarstate.leadTwo.status
 
     lead_xv_0 = self.process_lead(radarstate.leadOne)
@@ -327,7 +328,10 @@ class LongitudinalMpc():
     x_obstacles = np.column_stack([lead_0_obstacle, lead_1_obstacle, cruise_obstacle])
     self.source = SOURCES[np.argmin(x_obstacles[0])]
     self.params[:,2] = np.min(x_obstacles, axis=1)
-    self.params[:,3] = np.copy(self.prev_a)
+    if prev_accel_constraint:
+      self.params[:,3] = np.copy(self.prev_a)
+    else:
+      self.params[:,3] = a_ego
 
     self.run()
     if (np.any(lead_xv_0[:,0] - self.x_sol[:,0] < CRASH_DISTANCE) and
diff --git a/selfdrive/controls/lib/longitudinal_planner.py b/selfdrive/controls/lib/longitudinal_planner.py
index 80c8f3e6d7..1c1ab0e17b 100755
--- a/selfdrive/controls/lib/longitudinal_planner.py
+++ b/selfdrive/controls/lib/longitudinal_planner.py
@@ -67,10 +67,13 @@ class Planner:
     long_control_state = sm['controlsState'].longControlState
     force_slow_decel = sm['controlsState'].forceDecel
 
+    prev_accel_constraint = True
     enabled = (long_control_state == LongCtrlState.pid) or (long_control_state == LongCtrlState.stopping)
     if not enabled or sm['carState'].gasPressed:
       self.v_desired = v_ego
       self.a_desired = a_ego
+      # Smoothly changing between accel trajectory is only relevant when OP is driving
+      prev_accel_constraint = False
 
     # Prevent divergence, smooth in current v_ego
     self.v_desired = self.alpha * self.v_desired + (1 - self.alpha) * v_ego
@@ -87,7 +90,7 @@ class Planner:
     accel_limits_turns[1] = max(accel_limits_turns[1], self.a_desired - 0.05)
     self.mpc.set_accel_limits(accel_limits_turns[0], accel_limits_turns[1])
     self.mpc.set_cur_state(self.v_desired, self.a_desired)
-    self.mpc.update(sm['carState'], sm['radarState'], v_cruise)
+    self.mpc.update(sm['carState'], sm['radarState'], v_cruise, prev_accel_constraint=prev_accel_constraint)
     self.v_desired_trajectory = np.interp(T_IDXS[:CONTROL_N], T_IDXS_MPC, self.mpc.v_solution)
     self.a_desired_trajectory = np.interp(T_IDXS[:CONTROL_N], T_IDXS_MPC, self.mpc.a_solution)
     self.j_desired_trajectory = np.interp(T_IDXS[:CONTROL_N], T_IDXS_MPC[:-1], self.mpc.j_solution)
diff --git a/selfdrive/test/process_replay/ref_commit b/selfdrive/test/process_replay/ref_commit
index 44523319ee..95bf325d7c 100644
--- a/selfdrive/test/process_replay/ref_commit
+++ b/selfdrive/test/process_replay/ref_commit
@@ -1 +1 @@
-9cbef406393a83b35a8f25aa75099da8f8d68276
\ No newline at end of file
+6da38baefb2741902f8b10fbf2b5e64fd15ced1f
\ No newline at end of file