diff --git a/ChangeLog b/ChangeLog
index fe64cc2d65..d3b4844844 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+2016-11-17  Joseph Myers  <joseph@codesourcery.com>
+
+	* sysdeps/unix/sysv/linux/alpha/sys/user.h: Include <stddef.h>.
+
 2016-11-16  Joseph Myers  <joseph@codesourcery.com>
 
 	* conform/Makefile (linknamespace-libs): Rename to
diff --git a/sysdeps/unix/sysv/linux/alpha/sys/user.h b/sysdeps/unix/sysv/linux/alpha/sys/user.h
index 1a7c9c4889..3d0d76bc73 100644
--- a/sysdeps/unix/sysv/linux/alpha/sys/user.h
+++ b/sysdeps/unix/sysv/linux/alpha/sys/user.h
@@ -23,6 +23,7 @@
    than gdb/strace unless you know what you are doing. */
 
 #include <asm/reg.h>
+#include <stddef.h>
 
 struct user
 {