diff --git a/scripts/check-obsolete-constructs.py b/scripts/check-obsolete-constructs.py
index d230fcf892..f456c98def 100755
--- a/scripts/check-obsolete-constructs.py
+++ b/scripts/check-obsolete-constructs.py
@@ -605,7 +605,6 @@ HEADER_ALLOWED_INCLUDES = {
     "sys/signalfd.h":              [ "stdint.h" ],
     "sys/socketvar.h":             [ "sys/socket.h" ],
     "sys/timerfd.h":               [ "time.h" ],
-    "sys/timex.h":                 [ "sys/time.h" ],
     "sys/ttychars.h":              [ "sys/ttydefaults.h" ],
     "sys/ucontext.h":              [ "sys/procfs.h" ],
     "sys/vfs.h":                   [ "sys/statfs.h" ],
diff --git a/sysdeps/unix/sysv/linux/bits/timex.h b/sysdeps/unix/sysv/linux/bits/timex.h
index bb272e8b19..db36759fba 100644
--- a/sysdeps/unix/sysv/linux/bits/timex.h
+++ b/sysdeps/unix/sysv/linux/bits/timex.h
@@ -18,10 +18,16 @@
 #ifndef	_BITS_TIMEX_H
 #define	_BITS_TIMEX_H	1
 
+#if !defined _SYS_TIMEX_H && !defined _BITS_TIME_H
+# error "Never include <bits/timex.h> directly; use <sys/timex.h> instead."
+#endif
+
 #include <bits/types.h>
 #include <bits/types/struct_timeval.h>
 
-/* These definitions from linux/timex.h as of 3.18.  */
+/* These definitions match linux/timex.h as of 5.0.  */
+
+#define NTP_API	4		/* NTP API version */
 
 struct timex
 {
@@ -47,7 +53,7 @@ struct timex
 
   int tai;			/* TAI offset (ro) */
 
-  /* ??? */
+  /* room for future expansion */
   int  :32; int  :32; int  :32; int  :32;
   int  :32; int  :32; int  :32; int  :32;
   int  :32; int  :32; int  :32;
@@ -65,6 +71,7 @@ struct timex
 #define ADJ_MICRO		0x1000	/* select microsecond resolution */
 #define ADJ_NANO		0x2000	/* select nanosecond resolution */
 #define ADJ_TICK		0x4000	/* tick value */
+
 #define ADJ_OFFSET_SINGLESHOT	0x8001	/* old-fashioned adjtime */
 #define ADJ_OFFSET_SS_READ	0xa001	/* read-only adjtime */
 
@@ -107,4 +114,13 @@ struct timex
 #define STA_RONLY (STA_PPSSIGNAL | STA_PPSJITTER | STA_PPSWANDER \
     | STA_PPSERROR | STA_CLOCKERR | STA_NANO | STA_MODE | STA_CLK)
 
+/* Clock states (codes returned by adjtimex) */
+#define TIME_OK		0	/* clock synchronized, no leap second */
+#define TIME_INS	1	/* insert leap second */
+#define TIME_DEL	2	/* delete leap second */
+#define TIME_OOP	3	/* leap second in progress */
+#define TIME_WAIT	4	/* leap second has occurred */
+#define TIME_ERROR	5	/* clock not synchronized */
+#define TIME_BAD	TIME_ERROR /* bw compat */
+
 #endif /* bits/timex.h */
diff --git a/sysdeps/unix/sysv/linux/ntp_gettime.c b/sysdeps/unix/sysv/linux/ntp_gettime.c
index cff9b603e0..571339f5d7 100644
--- a/sysdeps/unix/sysv/linux/ntp_gettime.c
+++ b/sysdeps/unix/sysv/linux/ntp_gettime.c
@@ -21,10 +21,6 @@
 
 #undef ntp_gettime
 
-#ifndef MOD_OFFSET
-# define modes mode
-#endif
-
 
 int
 ntp_gettime (struct ntptimeval *ntv)
diff --git a/sysdeps/unix/sysv/linux/ntp_gettimex.c b/sysdeps/unix/sysv/linux/ntp_gettimex.c
index 044122bfd0..c83aa1e718 100644
--- a/sysdeps/unix/sysv/linux/ntp_gettimex.c
+++ b/sysdeps/unix/sysv/linux/ntp_gettimex.c
@@ -17,10 +17,6 @@
 
 #include <sys/timex.h>
 
-#ifndef MOD_OFFSET
-# define modes mode
-#endif
-
 
 int
 ntp_gettimex (struct ntptimeval *ntv)
diff --git a/sysdeps/unix/sysv/linux/sys/timex.h b/sysdeps/unix/sysv/linux/sys/timex.h
index c71ace1d3d..ee579466d1 100644
--- a/sysdeps/unix/sysv/linux/sys/timex.h
+++ b/sysdeps/unix/sysv/linux/sys/timex.h
@@ -19,14 +19,11 @@
 #define	_SYS_TIMEX_H	1
 
 #include <features.h>
-#include <sys/time.h>
-
-/* These definitions from linux/timex.h as of 2.6.30.  */
 
+/* Get struct timex and related constants.  */
 #include <bits/timex.h>
 
-#define NTP_API	4	/* NTP API version */
-
+/* Parameter structure used by ntp_gettime(x).  */
 struct ntptimeval
 {
   struct timeval time;	/* current time (ro) */
@@ -40,17 +37,6 @@ struct ntptimeval
   long int __glibc_reserved4;
 };
 
-/* Clock states (time_state) */
-#define TIME_OK		0	/* clock synchronized, no leap second */
-#define TIME_INS	1	/* insert leap second */
-#define TIME_DEL	2	/* delete leap second */
-#define TIME_OOP	3	/* leap second in progress */
-#define TIME_WAIT	4	/* leap second has occurred */
-#define TIME_ERROR	5	/* clock not synchronized */
-#define TIME_BAD	TIME_ERROR /* bw compat */
-
-/* Maximum time constant of the PLL.  */
-#define MAXTC		6
 
 __BEGIN_DECLS
 
