diff --git a/src/calibre/devices/__init__.py b/src/calibre/devices/__init__.py
index 022d4f8df3..24c6673dce 100644
--- a/src/calibre/devices/__init__.py
+++ b/src/calibre/devices/__init__.py
@@ -105,7 +105,7 @@ def debug(ioreg_to_tmp=False, buf=None, plugins=None,
         ioreg = None
         if isosx:
             from calibre.devices.usbms.device import Device
-            mount = repr(Device.osx_run_mount())
+            mount = '\n'.join(repr(x) for x in Device.osx_run_mount().splitlines())
             drives = pprint.pformat(Device.osx_get_usb_drives())
             ioreg = 'Output from mount:\n'+mount+'\n\n'
             ioreg += 'Output from osx_get_usb_drives:\n'+drives+'\n\n'