diff --git a/man2/setuid.2 b/man2/setuid.2
index 2ac27c6c1..d9a269791 100644
--- a/man2/setuid.2
+++ b/man2/setuid.2
@@ -105,6 +105,16 @@ If
 .I uid
 is different from the old effective UID, the process will
 be forbidden from leaving core dumps.
+
+The original Linux
+.BR setuid ()
+system call supported only 16-bit user IDs.
+Subsequently, Linux 2.4 added 
+.BR setuid32 ()
+supporting 32-bit IDs.
+The glibc
+.BR setuid ()
+wrapper function transparently deals with the variation across kernel versions.
 .SH "SEE ALSO"
 .BR getuid (2),
 .BR seteuid (2),