diff --git a/tools/ugv_cmd.py b/tools/ugv_cmd.py
index bd72d14..dd405a9 100755
--- a/tools/ugv_cmd.py
+++ b/tools/ugv_cmd.py
@@ -34,9 +34,9 @@ class CLI_CMD:
 cli_commands = []
 
 
-def cli_cmd(names=[], description=""):
+def cli_cmd(names=None, description=""):
     def dec(fn: types.FunctionType):
-        if len(dec.names) is 0:
+        if dec.names is None:
             dec.names = [fn.__name__]
         cli_commands.append(CLI_CMD(fn, dec.names, dec.description))
         return fn