diff --git a/ChangeLog b/ChangeLog
index 87f079da8d..8cec713550 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,14 @@
+2017-08-09  Dmitry V. Levin  <ldv@altlinux.org>
+
+	[BZ #21928]
+	* sysdeps/unix/sysv/linux/sys/ptrace.h (enum __ptrace_flags,
+	PTRACE_SEIZE_DEVEL): Remove.
+	* sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h: Likewise.
+	* sysdeps/unix/sysv/linux/ia64/sys/ptrace.h: Likewise.
+	* sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h: Likewise.
+	* sysdeps/unix/sysv/linux/s390/sys/ptrace.h: Likewise.
+	* sysdeps/unix/sysv/linux/sparc/sys/ptrace.h: Likewise.
+
 2017-08-09  Joseph Myers  <joseph@codesourcery.com>
 
 	* posix/bits/types.h (__qaddr_t): Remove.
diff --git a/NEWS b/NEWS
index 4b7e69a1db..484c467569 100644
--- a/NEWS
+++ b/NEWS
@@ -13,7 +13,8 @@ Major new features:
 
 Deprecated and removed features, and other changes affecting compatibility:
 
-  [Add deprecations, removals and changes affecting compatibility here]
+* On GNU/Linux, the obsolete Linux constant PTRACE_SEIZE_DEVEL is no longer
+  defined by <sys/ptrace.h>.
 
 Changes to build and runtime requirements:
 
diff --git a/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h b/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
index c8ca9e398e..479696d3d4 100644
--- a/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/aarch64/sys/ptrace.h
@@ -141,12 +141,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* Options set using PTRACE_SETOPTIONS.  */
 enum __ptrace_setoptions
 {
diff --git a/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h b/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
index c77e6dc683..681dc8913a 100644
--- a/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/ia64/sys/ptrace.h
@@ -146,12 +146,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* pt_all_user_regs is used for PTRACE_GETREGS/PTRACE_SETREGS.  */
 struct __pt_all_user_regs
   {
diff --git a/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h b/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
index ed1ed63cca..b2296fae10 100644
--- a/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/powerpc/sys/ptrace.h
@@ -133,12 +133,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* Options set using PTRACE_SETOPTIONS.  */
 enum __ptrace_setoptions
 {
diff --git a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
index e9136471f8..6c7d86ba32 100644
--- a/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/s390/sys/ptrace.h
@@ -210,12 +210,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* Options set using PTRACE_SETOPTIONS.  */
 enum __ptrace_setoptions
 {
diff --git a/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h b/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
index f60549427f..1fda17c772 100644
--- a/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/sparc/sys/ptrace.h
@@ -215,12 +215,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* Options set using PTRACE_SETOPTIONS.  */
 enum __ptrace_setoptions
 {
diff --git a/sysdeps/unix/sysv/linux/sys/ptrace.h b/sysdeps/unix/sysv/linux/sys/ptrace.h
index 1daadd1950..6ddd972aad 100644
--- a/sysdeps/unix/sysv/linux/sys/ptrace.h
+++ b/sysdeps/unix/sysv/linux/sys/ptrace.h
@@ -163,12 +163,6 @@ enum __ptrace_request
 };
 
 
-/* Flag for PTRACE_LISTEN.  */
-enum __ptrace_flags
-{
-  PTRACE_SEIZE_DEVEL = 0x80000000
-};
-
 /* Options set using PTRACE_SETOPTIONS.  */
 enum __ptrace_setoptions
 {