diff --git a/src/cockpit/channels/dbus.py b/src/cockpit/channels/dbus.py
index 664f181b3c3b..779a5216083a 100644
--- a/src/cockpit/channels/dbus.py
+++ b/src/cockpit/channels/dbus.py
@@ -45,6 +45,7 @@
 from cockpit._vendor.systemd_ctypes import Bus, BusError, introspection
 
 from ..channel import Channel, ChannelError
+from ..config import IS_LITTLE_ENDIAN_MACHINE
 
 logger = logging.getLogger(__name__)
 
@@ -174,6 +175,7 @@ class DBusChannel(Channel):
     name = None
     bus = None
     owner = None
+    endianness = "<" if IS_LITTLE_ENDIAN_MACHINE else ">"
 
     async def setup_name_owner_tracking(self):
         def send_owner(owner):
@@ -346,10 +348,9 @@ async def do_call(self, message):
             # If the method call has kicked off any signals related to
             # watch processing, wait for that to be done.
             async with self.watch_processing_lock:
-                # TODO: stop hard-coding the endian flag here.
                 self.send_json(
                     reply=[reply.get_body()], id=cookie,
-                    flags="<" if flags is not None else None,
+                    flags=self.endianness if flags is not None else None,
                     type=reply.get_signature(True))  # noqa: FBT003
         except BusError as error:
             # actually, should send the fields from the message body
diff --git a/src/cockpit/config.py b/src/cockpit/config.py
index 04d017e37e83..2647eaeceef8 100644
--- a/src/cockpit/config.py
+++ b/src/cockpit/config.py
@@ -18,6 +18,7 @@
 import configparser
 import logging
 import os
+import sys
 from pathlib import Path
 
 from cockpit._vendor.systemd_ctypes import bus
@@ -27,6 +28,7 @@
 XDG_CONFIG_HOME = Path(os.getenv('XDG_CONFIG_HOME') or os.path.expanduser('~/.config'))
 DOT_CONFIG_COCKPIT = XDG_CONFIG_HOME / 'cockpit'
 
+IS_LITTLE_ENDIAN_MACHINE = sys.byteorder == 'little'
 
 def lookup_config(filename: str) -> Path:
     config_dirs = os.environ.get('XDG_CONFIG_DIRS', '/etc').split(':')