diff --git a/src/header/mod.rs b/src/header/mod.rs
index 2760b38f87..09596767a6 100644
--- a/src/header/mod.rs
+++ b/src/header/mod.rs
@@ -55,6 +55,7 @@ pub mod sys_socket;
 pub mod sys_stat;
 pub mod sys_statvfs;
 pub mod sys_time;
+#[deprecated]
 pub mod sys_timeb;
 //pub mod sys_times;
 pub mod arch_aarch64_user;
diff --git a/src/header/sys_timeb/mod.rs b/src/header/sys_timeb/mod.rs
index c1e434bcd4..57c11e1c2b 100644
--- a/src/header/sys_timeb/mod.rs
+++ b/src/header/sys_timeb/mod.rs
@@ -1,10 +1,21 @@
-//! sys/time implementation for Redox, following http://pubs.opengroup.org/onlinepubs/7908799/xsh/systime.h.html
+//! `sys/timeb.h` implementation.
+//!
+//! See <https://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/timeb.h.html>.
+//!
+//! # Deprecation
+//! The `ftime()` function was marked as legacy in the Open Group Base
+//! Specifications Issue 6, and the entire `sys/timeb.h` header was removed in
+//! Issue 7.
+
+// TODO: set this for entire crate when possible
+#![deny(unsafe_op_in_unsafe_fn)]
 
 use crate::{
     header::sys_time::{gettimeofday, timeval, timezone},
     platform::types::*,
 };
 
+/// See <https://pubs.opengroup.org/onlinepubs/009695399/basedefs/sys/timeb.h.html>.
 #[repr(C)]
 #[derive(Default)]
 pub struct timeb {
@@ -14,18 +25,21 @@ pub struct timeb {
     pub dstflag: c_short,
 }
 
+/// See <https://pubs.opengroup.org/onlinepubs/009695399/functions/ftime.html>.
 #[no_mangle]
 pub unsafe extern "C" fn ftime(tp: *mut timeb) -> c_int {
+    let tp_mut = unsafe { &mut *tp };
+
     let mut tv = timeval::default();
     let mut tz = timezone::default();
-    if gettimeofday(&mut tv, &mut tz) < 0 {
+    if unsafe { gettimeofday(&mut tv, &mut tz) } < 0 {
         return -1;
     }
 
-    (*tp).time = tv.tv_sec;
-    (*tp).millitm = (tv.tv_usec / 1000) as c_ushort;
-    (*tp).timezone = tz.tz_minuteswest as c_short;
-    (*tp).dstflag = tz.tz_dsttime as c_short;
+    tp_mut.time = tv.tv_sec;
+    tp_mut.millitm = (tv.tv_usec / 1000) as c_ushort;
+    tp_mut.timezone = tz.tz_minuteswest as c_short;
+    tp_mut.dstflag = tz.tz_dsttime as c_short;
 
     0
 }