diff --git a/tools/rename_functions_in_ida.py b/tools/rename_functions_in_ida.py
index f2259796..9b3c127e 100644
--- a/tools/rename_functions_in_ida.py
+++ b/tools/rename_functions_in_ida.py
@@ -14,5 +14,5 @@ with open(csv_path, "r") as f:
     for fn in reader:
         addr = int(fn[0], 16)
         name = fn[3]
-        if name and fn[1] != "L":
+        if name and not name.startswith("nullsub_") and not name.startswith("sub_"):
             idc.set_name(addr, name)