diff --git a/selfdrive/debug/live_cpu_and_temp.py b/selfdrive/debug/live_cpu_and_temp.py
index baeebb1c4c..c35afc474b 100755
--- a/selfdrive/debug/live_cpu_and_temp.py
+++ b/selfdrive/debug/live_cpu_and_temp.py
@@ -1,10 +1,11 @@
 #!/usr/bin/env python3
 import argparse
 import capnp
+from collections import defaultdict
 
 from cereal.messaging import SubMaster
 from common.numpy_fast import mean
-from typing import Optional
+from typing import Optional, Dict
 
 def cputime_total(ct):
   return ct.user + ct.nice + ct.system + ct.idle + ct.iowait + ct.irq + ct.softirq
@@ -75,7 +76,7 @@ if __name__ == "__main__":
       print(f"CPU {100.0 * mean(cores):.2f}% - RAM: {last_mem:.2f}% - Temp {last_temp:.2f}C")
 
       if args.cpu and prev_proclog is not None and prev_proclog_t is not None:
-        procs = {}
+        procs: Dict[str, float] = defaultdict(float)
         dt = (sm.logMonoTime['procLog'] - prev_proclog_t) / 1e9
         for proc in m.procs:
           try:
@@ -83,12 +84,12 @@ if __name__ == "__main__":
             prev_proc = [p for p in prev_proclog.procs if proc.pid == p.pid][0]
             cpu_time = proc_cputime_total(proc) - proc_cputime_total(prev_proc)
             cpu_usage = cpu_time / dt * 100.
-            procs[name] = cpu_usage
+            procs[name] += cpu_usage
           except IndexError:
             pass
 
         print("Top CPU usage:")
-        for k, v in sorted(procs.items(), key=lambda item: item[1], reverse=True)[:10]:  # type: ignore
+        for k, v in sorted(procs.items(), key=lambda item: item[1], reverse=True)[:10]:
           print(f"{k.rjust(70)}   {v:.2f} %")
         print()