Terminal window has no name - 'Untitled Window'

The X Window that Terminal creates has no name set - it appears as 'Untitled Window' on my xfce panel and this is what `xwininfo` returns for it:

xwininfo: Window id: 0x660000a (has no name)

  Absolute upper-left X: 3840
  Absolute upper-left Y: 0
  Relative upper-left X: 0
  Relative upper-left Y: 0
  Width: 1920
  Height: 1080
  Depth: 32
  Visual: 0xc2
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x6600009 (not installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners: +3840+0 -0+0 -0-0 +3840-0
  -geometry 240x56-0+0

For comparison, this is the `xwininfo` for an xfce-terminal window:

xwininfo: Window id: 0x4e086ec "Terminal"

  Absolute upper-left X: 2233
  Absolute upper-left Y: 75
  Relative upper-left X: 1
  Relative upper-left Y: 24
  Width: 1067
  Height: 874
  Depth: 32
  Visual: 0x104
  Visual Class: TrueColor
  Border width: 0
  Class: InputOutput
  Colormap: 0x4e00003 (not installed)
  Bit Gravity State: NorthWestGravity
  Window Gravity State: NorthWestGravity
  Backing Store State: NotUseful
  Save Under State: no
  Map State: IsViewable
  Override Redirect State: no
  Corners: +2233+75 -2460+75 -2460-131 +2233-131
  -geometry 150x50+2232+51

This is the version or pantheon-terminal I'm using:

 ➜ pantheon-terminal --version
[INFO 14:24:41.131476] Application.vala:155: Terminal version: 0.4.0.2
[INFO 14:24:41.131496] Application.vala:157: Kernel version: 4.4.0-45-generic
[DEBUG 14:24:41.132026] Settings.vala:163: Loading settings from schema 'org.pantheon.terminal.saved-state'
[DEBUG 14:24:41.132312] Settings.vala:163: Loading settings from schema 'org.pantheon.terminal.settings'

and running on XUbuntu Xenial:

 ➜ lsb_release -a
LSB Version: core-9.20160110ubuntu0.2-amd64:core-9.20160110ubuntu0.2-noarch:printing-9.20160110ubuntu0.2-amd64:printing-9.20160110ubuntu0.2-noarch:security-9.20160110ubuntu0.2-amd64:security-9.20160110ubuntu0.2-noarch
Distributor ID: Ubuntu
Description: Ubuntu 16.04.1 LTS
Release: 16.04
Codename: xenial