diff --git a/selfdrive/debug/can_printer.py b/selfdrive/debug/can_printer.py
index 7ea26d62fc..935065b804 100755
--- a/selfdrive/debug/can_printer.py
+++ b/selfdrive/debug/can_printer.py
@@ -1,25 +1,23 @@
 #!/usr/bin/env python3
+import argparse
 import binascii
-import os
-import sys
 from collections import defaultdict
 
 import cereal.messaging as messaging
 from common.realtime import sec_since_boot
 
 
-def can_printer(bus=0, max_msg=None, addr="127.0.0.1"):
+def can_printer(bus, max_msg, addr):
   logcan = messaging.sub_sock('can', addr=addr)
 
   start = sec_since_boot()
   lp = sec_since_boot()
   msgs = defaultdict(list)
-  canbus = int(os.getenv("CAN", bus))
   while 1:
     can_recv = messaging.drain_sock(logcan, wait_for_one=True)
     for x in can_recv:
       for y in x.can:
-        if y.src == canbus:
+        if y.src == bus:
           msgs[y.address].append(y.dat)
 
     if sec_since_boot() - lp > 0.1:
@@ -32,11 +30,12 @@ def can_printer(bus=0, max_msg=None, addr="127.0.0.1"):
       lp = sec_since_boot()
 
 if __name__ == "__main__":
-  if len(sys.argv) > 3:
-    can_printer(int(sys.argv[1]), int(sys.argv[2]), sys.argv[3])
-  elif len(sys.argv) > 2:
-    can_printer(int(sys.argv[1]), int(sys.argv[2]))
-  elif len(sys.argv) > 1:
-    can_printer(int(sys.argv[1]))
-  else:
-    can_printer()
+  parser = argparse.ArgumentParser(description="PlotJuggler plugin for reading openpilot logs",
+                                   formatter_class=argparse.ArgumentDefaultsHelpFormatter)
+
+  parser.add_argument("--bus", help="CAN bus to print out", default=0)
+  parser.add_argument("--max_msg", help="max addr ")
+  parser.add_argument("--addr", default="127.0.0.1")
+
+  args = parser.parse_args()
+  can_printer(args.bus, args.max_msg, args.addr)