diff --git a/gp2040ce_bintools/builder.py b/gp2040ce_bintools/builder.py
index bee2a2e..2d96d1f 100644
--- a/gp2040ce_bintools/builder.py
+++ b/gp2040ce_bintools/builder.py
@@ -10,6 +10,7 @@ import os
 import re
 from typing import Optional
 
+from google.protobuf.json_format import MessageToJson
 from google.protobuf.message import Message
 
 import gp2040ce_bintools.storage as storage
@@ -248,15 +249,19 @@ def write_new_config_to_filename(config: Message, filename: str, inject: bool =
         with open(filename, 'wb') as file:
             file.write(binary)
     else:
-        binary = storage.serialize_config_with_footer(config)
-        with open(filename, 'wb') as file:
-            if filename[-4:] == '.uf2':
-                # we must pad to storage start in order for the UF2 write addresses to make sense
-                file.write(storage.convert_binary_to_uf2([
-                    (storage.USER_CONFIG_BINARY_LOCATION, storage.pad_config_to_storage_size(binary)),
-                ]))
-            else:
-                file.write(binary)
+        if filename[-5:] == '.json':
+            with open(filename, 'w') as file:
+                file.write(MessageToJson(config))
+        else:
+            binary = storage.serialize_config_with_footer(config)
+            with open(filename, 'wb') as file:
+                if filename[-4:] == '.uf2':
+                    # we must pad to storage start in order for the UF2 write addresses to make sense
+                    file.write(storage.convert_binary_to_uf2([
+                        (storage.USER_CONFIG_BINARY_LOCATION, storage.pad_config_to_storage_size(binary)),
+                    ]))
+                else:
+                    file.write(binary)
 
 
 def write_new_config_to_usb(config: Message, endpoint_out: object, endpoint_in: object):
diff --git a/tests/test_builder.py b/tests/test_builder.py
index 1857be3..e2812d1 100644
--- a/tests/test_builder.py
+++ b/tests/test_builder.py
@@ -3,6 +3,7 @@
 SPDX-FileCopyrightText: © 2023 Brian S. Stephan <bss@incorporeal.org>
 SPDX-License-Identifier: GPL-3.0-or-later
 """
+import logging
 import math
 import os
 import sys
@@ -14,10 +15,12 @@ from decorator import decorator
 import gp2040ce_bintools.builder as builder
 from gp2040ce_bintools import get_config_pb2
 from gp2040ce_bintools.storage import (STORAGE_SIZE, get_board_storage_section, get_config, get_config_footer,
-                                       get_user_storage_section, serialize_config_with_footer)
+                                       get_config_from_json, get_user_storage_section, serialize_config_with_footer)
 
 HERE = os.path.dirname(os.path.abspath(__file__))
 
+logger = logging.getLogger(__name__)
+
 
 @decorator
 def with_pb2s(test, *args, **kwargs):
@@ -351,6 +354,21 @@ def test_write_new_config_to_config_uf2(firmware_binary, tmp_path):
     assert len(config_dump) == STORAGE_SIZE * 2
 
 
+@with_pb2s
+def test_write_new_config_to_config_json(config_binary, tmp_path):
+    """Test that the config can be written to a file."""
+    tmp_file = os.path.join(tmp_path, 'config.json')
+    config = get_config(config_binary)
+    builder.write_new_config_to_filename(config, tmp_file)
+
+    # read new file
+    with open(tmp_file, 'r') as file:
+        config_dump = file.read()
+    logger.debug(config_dump)
+    config = get_config_from_json(config_dump)
+    assert config.boardVersion == 'v0.7.5'
+
+
 @with_pb2s
 def test_write_new_config_to_usb(config_binary):
     """Test that the config can be written to USB at the proper alignment."""