diff --git a/TODO b/TODO
index 7190d42b0..5434c6f7d 100644
--- a/TODO
+++ b/TODO
@@ -12,6 +12,8 @@
  * Make sure the mouse is where it's supposed to be when un-grabbed
  * Test native window codepath
  * Add keyboard enumeration / name query API
+ * Implement NET_WM_PING and NET_WM_PID/WM_CLIENT_MACHINE (?)
+   - http://standards.freedesktop.org/wm-spec/wm-spec-1.3.html#KILLINGWINDOWS
 
 Wish list for the 1.3 development branch:
 http://bugzilla.libsdl.org/