diff --git a/cereal b/cereal
index 3be0bf50c8..bab2f2b95e 160000
--- a/cereal
+++ b/cereal
@@ -1 +1 @@
-Subproject commit 3be0bf50c801f4d01f92ee08cebcf960f09b180d
+Subproject commit bab2f2b95e38da4c968efc31369163056e938b30
diff --git a/selfdrive/locationd/locationd.cc b/selfdrive/locationd/locationd.cc
index dcdae4e84b..08f105dd99 100755
--- a/selfdrive/locationd/locationd.cc
+++ b/selfdrive/locationd/locationd.cc
@@ -340,8 +340,8 @@ kj::ArrayPtr<capnp::byte> Localizer::get_message_bytes(MessageBuilder& msg_build
 int Localizer::locationd_thread() {
   const std::initializer_list<const char *> service_list =
       { "gpsLocationExternal", "sensorEvents", "cameraOdometry", "liveCalibration", "carState" };
-  SubMaster sm(service_list, nullptr, { "gpsLocationExternal" });
   PubMaster pm({ "liveLocationKalman" });
+  SubMaster sm(service_list, nullptr, { "gpsLocationExternal" });
 
   Params params;
 
diff --git a/selfdrive/locationd/ubloxd.cc b/selfdrive/locationd/ubloxd.cc
index 7b3c3039bd..a0b4ef7fad 100644
--- a/selfdrive/locationd/ubloxd.cc
+++ b/selfdrive/locationd/ubloxd.cc
@@ -13,12 +13,13 @@ int main() {
   AlignedBuffer aligned_buf;
   UbloxMsgParser parser;
 
+  PubMaster pm({"ubloxGnss", "gpsLocationExternal"});
+
   Context * context = Context::create();
   SubSocket * subscriber = SubSocket::create(context, "ubloxRaw");
   assert(subscriber != NULL);
   subscriber->setTimeout(100);
 
-  PubMaster pm({"ubloxGnss", "gpsLocationExternal"});
 
   while (!do_exit) {
     Message * msg = subscriber->receive();
diff --git a/selfdrive/test/process_replay/process_replay.py b/selfdrive/test/process_replay/process_replay.py
index 1873340495..36125826e6 100755
--- a/selfdrive/test/process_replay/process_replay.py
+++ b/selfdrive/test/process_replay/process_replay.py
@@ -432,32 +432,38 @@ def python_replay_process(cfg, lr, fingerprint=None):
 def cpp_replay_process(cfg, lr, fingerprint=None):
   sub_sockets = [s for _, sub in cfg.pub_sub.items() for s in sub]  # We get responses here
   pm = messaging.PubMaster(cfg.pub_sub.keys())
-  sockets = {s: messaging.sub_sock(s, timeout=1000) for s in sub_sockets}
 
   all_msgs = sorted(lr, key=lambda msg: msg.logMonoTime)
   pub_msgs = [msg for msg in all_msgs if msg.which() in list(cfg.pub_sub.keys())]
 
+  os.environ["SIMULATION"] = "1"  # Disable submaster alive checks
   managed_processes[cfg.proc_name].prepare()
   managed_processes[cfg.proc_name].start()
 
-  time.sleep(1)  # We give the process time to start
+  while not all(pm.all_readers_updated(s) for s in cfg.pub_sub.keys()):
+    time.sleep(0)
 
-  log_msgs = []
+  # Make sure all subscribers are connected
+  sockets = {s: messaging.sub_sock(s, timeout=1000) for s in sub_sockets}
   for s in sub_sockets:
     messaging.recv_one_or_none(sockets[s])
 
-  for msg in tqdm(pub_msgs, disable=CI):
+  log_msgs = []
+  for i, msg in enumerate(tqdm(pub_msgs, disable=CI)):
     pm.send(msg.which(), msg.as_builder())
+
     resp_sockets = cfg.pub_sub[msg.which()] if cfg.should_recv_callback is None else cfg.should_recv_callback(msg)
     for s in resp_sockets:
       response = messaging.recv_one(sockets[s])
-      if response is not None:
+
+      if response is None:
+        print(f"Warning, no response received {i}")
+      else:
         log_msgs.append(response)
 
-    if not len(resp_sockets):
+    if not len(resp_sockets):  # We only need to wait if we didn't already wait for a response
       while not pm.all_readers_updated(msg.which()):
         time.sleep(0)
-      time.sleep(0.0001)
 
   managed_processes[cfg.proc_name].stop()
   return log_msgs