diff --git a/selfdrive/debug/check_can_parser_performance.py b/selfdrive/debug/check_can_parser_performance.py
index 07e9c55281a04d..a5155f0126b8dc 100755
--- a/selfdrive/debug/check_can_parser_performance.py
+++ b/selfdrive/debug/check_can_parser_performance.py
@@ -29,9 +29,10 @@ class CarModelTestCase(TestCarModelBase):
     msgs = [m.as_builder().to_bytes() for m in tm.can_msgs]
     start_t = time.process_time_ns()
     for msg in msgs:
+      can_list = can_capnp_to_list([msg])
       for cp in tm.CI.can_parsers:
         if cp is not None:
-          cp.update_strings(can_capnp_to_list([msg]))
+          cp.update_strings(can_list)
     ets.append((time.process_time_ns() - start_t) * 1e-6)
 
   print(f'{len(tm.can_msgs)} CAN packets, {N_RUNS} runs')