diff --git a/lib/libsys/lseek.2 b/lib/libsys/lseek.2
index 6df543d8ce7..7fabe8fc3b4 100644
--- a/lib/libsys/lseek.2
+++ b/lib/libsys/lseek.2
@@ -209,7 +209,8 @@ and
 .Dv SEEK_DATA
 directives, along with the
 .Er ENXIO
-error, are extensions to that specification.
+error, are expected to conform to
+.St -p1003.1-2024 .
 .Sh HISTORY
 The
 .Fn lseek