diff --git a/selfdrive/test/process_replay/process_replay.py b/selfdrive/test/process_replay/process_replay.py
index 8f2f3e1bd6..d6d5b25bde 100755
--- a/selfdrive/test/process_replay/process_replay.py
+++ b/selfdrive/test/process_replay/process_replay.py
@@ -2,6 +2,7 @@
 import os
 import time
 import signal
+import platform
 from collections import OrderedDict
 from dataclasses import dataclass, field
 from typing import Dict, List, Optional, Callable
@@ -417,8 +418,11 @@ def replay_process(cfg, lr, fingerprint=None):
       return log_msgs
 
 
-def setup_env(CP=None, cfg=None, controlsState=None, lr=None, fingerprint=None):
-  os.environ["PARAMS_ROOT"] = "/dev/shm/params"
+def setup_env(CP=None, cfg=None, controlsState=None, lr=None, fingerprint=None, log_dir=None):
+  if platform.system() != "Darwin":
+    os.environ["PARAMS_ROOT"] = "/dev/shm/params"
+  if log_dir is not None:
+    os.environ["LOG_ROOT"] = log_dir
 
   params = Params()
   params.clear_all()
diff --git a/selfdrive/test/process_replay/regen.py b/selfdrive/test/process_replay/regen.py
index fbabc1bd29..63eb37d29d 100755
--- a/selfdrive/test/process_replay/regen.py
+++ b/selfdrive/test/process_replay/regen.py
@@ -243,15 +243,14 @@ def regen_segment(lr, frs=None, daemons="all", outdir=FAKEDATA, disable_tqdm=Fal
   if frs is None:
     frs = dict()
 
-  params = Params()
-  os.environ["LOG_ROOT"] = outdir
-
   # Get and setup initial state
   CP = [m for m in lr if m.which() == 'carParams'][0].carParams
   controlsState = [m for m in lr if m.which() == 'controlsState'][0].controlsState
   liveCalibration = [m for m in lr if m.which() == 'liveCalibration'][0]
 
-  setup_env(CP=CP, controlsState=controlsState)
+  setup_env(CP=CP, controlsState=controlsState, log_dir=outdir)
+
+  params = Params()
   params.put("CalibrationParams", liveCalibration.as_builder().to_bytes())
 
   vs, cam_procs = replay_cameras(lr, frs, disable_tqdm=disable_tqdm)