diff --git a/docs/release-notes.rst b/docs/release-notes.rst
index 2843ac9..85b4032 100644
--- a/docs/release-notes.rst
+++ b/docs/release-notes.rst
@@ -26,6 +26,7 @@ Improvements
 - DSO Driver function 'waveform_values' now returns a single channels x and y data as two separate lists, without re-acquiring the signal. This function should
   now be called after performing signal acquisition.
 - Invert channel and vtime funcitons implemented in the DSO driver.
+- Fxconfig fixes for cmd2 4.0.0
 
 *************
 Version 0.6.4
diff --git a/src/fixate/core/config_util.py b/src/fixate/core/config_util.py
index 6e6f481..ea7b85d 100644
--- a/src/fixate/core/config_util.py
+++ b/src/fixate/core/config_util.py
@@ -1,5 +1,4 @@
 import cmd2
-import argparse
 import pyvisa
 import json
 import copy
@@ -36,13 +35,13 @@
 
 choices = ["existing", "updated", "visa"]
 # create the top-level parser for the base command
-list_parser = argparse.ArgumentParser(prog="list")
+list_parser = cmd2.Cmd2ArgumentParser(prog="list")
 list_parser.add_argument("type", choices=choices)
 
-test_parser = argparse.ArgumentParser(prog="test")
+test_parser = cmd2.Cmd2ArgumentParser(prog="test")
 test_parser.add_argument("type", choices=choices)
 
-add_parser = argparse.ArgumentParser(prog="add")
+add_parser = cmd2.Cmd2ArgumentParser(prog="add")
 add_subparsers = add_parser.add_subparsers(title="add command")
 
 add_visa_parser = add_subparsers.add_parser("visa")
@@ -215,7 +214,7 @@ def do_save(self, line=None):
                     )
             except Exception as e:
                 self.perror(e)
-                if backup_file:
+                if backup_path:
                     backup_path.replace(config_file_path)
                 raise