diff --git a/TODO b/TODO
index 922c2241e88317c424541f57db193d6c848815d4..ab51c01ef40eaf2fa1d08308c3efa05c94f9d0cb 100644
--- a/TODO
+++ b/TODO
@@ -25,6 +25,7 @@ Version 1.5.0:
 * Bus simulator interface.
 * Implement ecrt_master_slave() in kernel space.
 * Rename phy-commands to register commands.
+* Check for ioctl() interface version.
 
 Future issues: