diff --git a/man2/ioctl_list.2 b/man2/ioctl_list.2
index ba993a104..d0390c7e2 100644
--- a/man2/ioctl_list.2
+++ b/man2/ioctl_list.2
@@ -738,6 +738,13 @@ l l l l.
 0xC0044DFF	SOUND_MIXER_WRITE_RECSRC	int *	// I-O
 .TE
 
+// <include/linux/timerfd.h> see
+.BR timerfd_create (2)
+.TS
+l l l l.
+0x40085400	TFD_IOC_SET_TICKS	uint64_t *
+.TE
+
 // <include/linux/umsdos_fs.h>
 .TS
 l l l l.