diff --git a/include/unistd.h b/include/unistd.h
index 1bfe0aa9102a..a1d68810470b 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: unistd.h,v 1.165 2024/05/19 22:25:47 christos Exp $	*/
+/*	$NetBSD: unistd.h,v 1.166 2024/05/20 01:30:33 christos Exp $	*/
 
 /*-
  * Copyright (c) 1998, 1999, 2008 The NetBSD Foundation, Inc.
@@ -330,7 +330,7 @@ int	 closefrom(int);
 int	 des_cipher(const char *, char *, long, int);
 int	 des_setkey(const char *);
 #ifndef __LIBC12_SOURCE__
-int	 dup3(int, int, int) __RENAME(__dup3110);
+int	 dup3(int, int, int) __RENAME(__dup3100);
 #endif
 void	 endusershell(void);
 int	 exect(const char *, char * const *, char * const *);
diff --git a/lib/libc/sys/Makefile.inc b/lib/libc/sys/Makefile.inc
index 1abf57f11360..acb1d4330661 100644
--- a/lib/libc/sys/Makefile.inc
+++ b/lib/libc/sys/Makefile.inc
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile.inc,v 1.254 2024/05/19 22:25:48 christos Exp $
+#	$NetBSD: Makefile.inc,v 1.255 2024/05/20 01:30:33 christos Exp $
 #	@(#)Makefile.inc	8.3 (Berkeley) 10/24/94
 
 # sys sources
@@ -102,7 +102,7 @@ ASM=\
 	chdir.S chflags.S chmod.S chown.S chroot.S \
 		clock_getcpuclockid2.S \
 		__clock_getres50.S __clock_gettime50.S \
-	dup.S dup2.S __dup3110.S \
+	dup.S dup2.S __dup3100.S \
 	eventfd.S \
 	extattrctl.S \
 		extattr_delete_fd.S extattr_delete_file.S \
diff --git a/sys/compat/common/compat_100_mod.c b/sys/compat/common/compat_100_mod.c
index 89020902edb3..f195994e56ac 100644
--- a/sys/compat/common/compat_100_mod.c
+++ b/sys/compat/common/compat_100_mod.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: compat_100_mod.c,v 1.2 2023/07/28 18:19:00 christos Exp $ */
+/*	$NetBSD: compat_100_mod.c,v 1.3 2024/05/20 01:30:34 christos Exp $ */
 
 /*-
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: compat_100_mod.c,v 1.2 2023/07/28 18:19:00 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: compat_100_mod.c,v 1.3 2024/05/20 01:30:34 christos Exp $");
 
 #include <sys/systm.h>
 #include <sys/module.h>
@@ -49,15 +49,23 @@ __KERNEL_RCSID(0, "$NetBSD: compat_100_mod.c,v 1.2 2023/07/28 18:19:00 christos
 int
 compat_100_init(void)
 {
+	int error;
 
-	return kern_event_100_init();
+	error = kern_event_100_init();
+	if (error)
+		return error;
+	return sys_descrip_100_init();
 }
 
 int
 compat_100_fini(void)
 {
+	int error;
 
-	return kern_event_100_fini();
+	error = kern_event_100_fini();
+	if (error)
+		return error;
+	return sys_descrip_100_fini();
 }
 
 MODULE(MODULE_CLASS_EXEC, compat_100, NULL);
diff --git a/sys/compat/common/compat_110_mod.c b/sys/compat/common/compat_110_mod.c
index 9e2d6a2e105e..dcb33365d944 100644
--- a/sys/compat/common/compat_110_mod.c
+++ b/sys/compat/common/compat_110_mod.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: compat_110_mod.c,v 1.1 2024/05/19 22:25:48 christos Exp $ */
+/*	$NetBSD: compat_110_mod.c,v 1.2 2024/05/20 01:30:34 christos Exp $ */
 
 /*-
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -38,7 +38,7 @@
 #endif
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: compat_110_mod.c,v 1.1 2024/05/19 22:25:48 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: compat_110_mod.c,v 1.2 2024/05/20 01:30:34 christos Exp $");
 
 #include <sys/systm.h>
 #include <sys/module.h>
@@ -49,15 +49,13 @@ __KERNEL_RCSID(0, "$NetBSD: compat_110_mod.c,v 1.1 2024/05/19 22:25:48 christos
 int
 compat_110_init(void)
 {
-
-	return sys_descrip_110_init();
+	return 0;
 }
 
 int
 compat_110_fini(void)
 {
-
-	return sys_descrip_110_fini();
+	return 0;
 }
 
 MODULE(MODULE_CLASS_EXEC, compat_110, NULL);
diff --git a/sys/compat/common/compat_mod.h b/sys/compat/common/compat_mod.h
index 276bd4d6accb..f0ab23798fc4 100644
--- a/sys/compat/common/compat_mod.h
+++ b/sys/compat/common/compat_mod.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: compat_mod.h,v 1.11 2024/05/19 22:25:48 christos Exp $	*/
+/*	$NetBSD: compat_mod.h,v 1.12 2024/05/20 01:30:34 christos Exp $	*/
 
 /*-
  * Copyright (c) 2013, 2019 The NetBSD Foundation, Inc.
@@ -35,8 +35,6 @@
 #ifdef COMPAT_110
 int compat_110_init(void);
 int compat_110_fini(void);
-int sys_descrip_110_init(void);
-int sys_descrip_110_fini(void);
 #endif
 
 #ifdef COMPAT_100
@@ -44,6 +42,8 @@ int compat_100_init(void);
 int compat_100_fini(void);
 int kern_event_100_init(void);
 int kern_event_100_fini(void);
+int sys_descrip_100_init(void);
+int sys_descrip_100_fini(void);
 #endif
 
 #ifdef COMPAT_90
diff --git a/sys/compat/common/files.common b/sys/compat/common/files.common
index d63d9a5dc331..8a55a78df3ff 100644
--- a/sys/compat/common/files.common
+++ b/sys/compat/common/files.common
@@ -1,4 +1,4 @@
-#	$NetBSD: files.common,v 1.12 2024/05/19 22:25:48 christos Exp $
+#	$NetBSD: files.common,v 1.13 2024/05/20 01:30:34 christos Exp $
 
 #
 # Generic utility files, used by various compat options.
@@ -114,10 +114,11 @@ file	compat/common/net_inet6_nd_90.c		compat_90
 # Compatibility code for NetBSD 10.0
 file	compat/common/compat_100_mod.c		compat_100
 file	compat/common/kern_event_100.c		compat_100
+file	compat/common/compat_100_mod.c		compat_100
+file	compat/common/sys_descrip_100.c		compat_100
 
 # Compatibility code for NetBSD 11.0
 file	compat/common/compat_110_mod.c		compat_110
-file	compat/common/sys_descrip_110.c		compat_110
 
 #
 # Sources for sysv ipc compatibility across the versions.
diff --git a/sys/compat/common/sys_decrip_110.c b/sys/compat/common/sys_descrip_100.c
similarity index 93%
rename from sys/compat/common/sys_decrip_110.c
rename to sys/compat/common/sys_descrip_100.c
index 4ba16696dc18..2d9abc15d9eb 100644
--- a/sys/compat/common/sys_decrip_110.c
+++ b/sys/compat/common/sys_descrip_100.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: sys_decrip_110.c,v 1.1 2024/05/19 22:25:48 christos Exp $	*/
+/*	$NetBSD: sys_descrip_100.c,v 1.1 2024/05/20 01:30:34 christos Exp $	*/
 
 /*-
  * Copyright (c) 2024 The NetBSD Foundation, Inc.
@@ -26,7 +26,7 @@
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: sys_decrip_110.c,v 1.1 2024/05/19 22:25:48 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: sys_descrip_100.c,v 1.1 2024/05/20 01:30:34 christos Exp $");
 
 #if defined(_KERNEL_OPT)
 #include "opt_compat_netbsd.h"
diff --git a/sys/compat/netbsd32/netbsd32_compat_100.c b/sys/compat/netbsd32/netbsd32_compat_100.c
index 68c3c5a19ad7..0acc1ffe6c87 100644
--- a/sys/compat/netbsd32/netbsd32_compat_100.c
+++ b/sys/compat/netbsd32/netbsd32_compat_100.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: netbsd32_compat_100.c,v 1.3 2023/07/29 12:48:15 rin Exp $ */
+/*	$NetBSD: netbsd32_compat_100.c,v 1.4 2024/05/20 01:30:33 christos Exp $ */
 
 /*-
  * Copyright (c) 2019 The NetBSD Foundation, Inc.
@@ -30,9 +30,10 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_100.c,v 1.3 2023/07/29 12:48:15 rin Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_100.c,v 1.4 2024/05/20 01:30:33 christos Exp $");
 
 #include <sys/types.h>
+#include <sys/filedesc.h>
 #include <sys/event.h>
 #include <sys/eventvar.h>
 #include <sys/module.h>
@@ -129,9 +130,29 @@ compat_100_netbsd32___kevent50(struct lwp *l,
 	    SCARG(uap, timeout), &netbsd32_kevent_ops);
 }
 
+int
+compat_100_netbsd32_dup3(struct lwp *l,
+    const struct compat_100_netbsd32_dup3_args *uap, register_t *retval)
+{
+	/* {
+		syscallarg(int) from;
+		syscallarg(int) to;
+		syscallarg(int) flags;
+		syscallarg(const netbsd32_kevent100p_t) changelist;
+		syscallarg(netbsd32_size_t) nchanges;
+		syscallarg(netbsd32_kevent100p_t) eventlist;
+		syscallarg(netbsd32_size_t) nevents;
+		syscallarg(netbsd32_timespecp_t) timeout;
+	} */
+	return dodup(l, SCARG(uap, from), SCARG(uap, to), SCARG(uap, flags),
+	    retval);
+}
+
 static struct syscall_package compat_netbsd32_100_syscalls[] = {
 	{ NETBSD32_SYS_compat_100_netbsd32___kevent50, 0,
 	    (sy_call_t *)compat_100_netbsd32___kevent50 },
+	{ NETBSD32_SYS_compat_100_netbsd32_dup3, 0,
+	    (sy_call_t *)compat_100_netbsd32_dup3 },
 	{ 0, 0, NULL },
 };
 
diff --git a/sys/compat/netbsd32/netbsd32_compat_110.c b/sys/compat/netbsd32/netbsd32_compat_110.c
index 5413e9e24b76..d0a5e2f4a519 100644
--- a/sys/compat/netbsd32/netbsd32_compat_110.c
+++ b/sys/compat/netbsd32/netbsd32_compat_110.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: netbsd32_compat_110.c,v 1.1 2024/05/19 22:25:48 christos Exp $ */
+/*	$NetBSD: netbsd32_compat_110.c,v 1.2 2024/05/20 01:30:33 christos Exp $ */
 
 /*-
  * Copyright (c) 2024 The NetBSD Foundation, Inc.
@@ -30,10 +30,9 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_110.c,v 1.1 2024/05/19 22:25:48 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_110.c,v 1.2 2024/05/20 01:30:33 christos Exp $");
 
 #include <sys/types.h>
-#include <sys/filedesc.h>
 #include <sys/module.h>
 #include <sys/syscallvar.h>
 #include <sys/syscallargs.h>
@@ -43,27 +42,8 @@ __KERNEL_RCSID(0, "$NetBSD: netbsd32_compat_110.c,v 1.1 2024/05/19 22:25:48 chri
 #include <compat/netbsd32/netbsd32_syscall.h>
 #include <compat/netbsd32/netbsd32_syscallargs.h>
 
-int
-compat_110_netbsd32_dup3(struct lwp *l,
-    const struct compat_110_netbsd32_dup3_args *uap, register_t *retval)
-{
-	/* {
-		syscallarg(int) from;
-		syscallarg(int) to;
-		syscallarg(int) flags;
-		syscallarg(const netbsd32_kevent100p_t) changelist;
-		syscallarg(netbsd32_size_t) nchanges;
-		syscallarg(netbsd32_kevent100p_t) eventlist;
-		syscallarg(netbsd32_size_t) nevents;
-		syscallarg(netbsd32_timespecp_t) timeout;
-	} */
-	return dodup(l, SCARG(uap, from), SCARG(uap, to), SCARG(uap, flags),
-	    retval);
-}
 
 static struct syscall_package compat_netbsd32_110_syscalls[] = {
-	{ NETBSD32_SYS_compat_110_netbsd32_dup3, 0,
-	    (sy_call_t *)compat_110_netbsd32_dup3 },
 	{ 0, 0, NULL },
 };
 
diff --git a/sys/compat/netbsd32/netbsd32_netbsd.c b/sys/compat/netbsd32/netbsd32_netbsd.c
index 4133d2ac98b8..777ca41c9fe0 100644
--- a/sys/compat/netbsd32/netbsd32_netbsd.c
+++ b/sys/compat/netbsd32/netbsd32_netbsd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: netbsd32_netbsd.c,v 1.236 2024/05/19 22:25:48 christos Exp $	*/
+/*	$NetBSD: netbsd32_netbsd.c,v 1.237 2024/05/20 01:30:33 christos Exp $	*/
 
 /*
  * Copyright (c) 1998, 2001, 2008, 2018 Matthew R. Green
@@ -27,7 +27,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: netbsd32_netbsd.c,v 1.236 2024/05/19 22:25:48 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: netbsd32_netbsd.c,v 1.237 2024/05/20 01:30:33 christos Exp $");
 
 /*
  * below are all the standard NetBSD system calls, in the 32bit
@@ -2462,21 +2462,21 @@ netbsd32__sched_protect(struct lwp *l,
 }
 
 int
-netbsd32___dup3110(struct lwp *l, const struct netbsd32___dup3110_args *uap,
-	      register_t *retval)
+netbsd32___dup3100(struct lwp *l, const struct netbsd32___dup3100_args *uap,
+    register_t *retval)
 {
 	/* {
 		syscallarg(int) from;
 		syscallarg(int) to;
 		syscallarg(int) flags;
 	} */
-	struct sys___dup3110_args ua;
+	struct sys___dup3100_args ua;
 
 	NETBSD32TO64_UAP(from);
 	NETBSD32TO64_UAP(to);
 	NETBSD32TO64_UAP(flags);
 
-	return sys___dup3110(l, &ua, retval);
+	return sys___dup3100(l, &ua, retval);
 }
 
 int
diff --git a/sys/compat/netbsd32/syscalls.master b/sys/compat/netbsd32/syscalls.master
index 481579647da9..2f6c4268977d 100644
--- a/sys/compat/netbsd32/syscalls.master
+++ b/sys/compat/netbsd32/syscalls.master
@@ -1,4 +1,4 @@
-	$NetBSD: syscalls.master,v 1.145 2024/05/19 22:25:48 christos Exp $
+	$NetBSD: syscalls.master,v 1.146 2024/05/20 01:30:33 christos Exp $
 
 ;	from: NetBSD: syscalls.master,v 1.81 1998/07/05 08:49:50 jonathan Exp
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
@@ -1069,7 +1069,7 @@
 			    netbsd32_size_t fh_size, netbsd32_statp_t sb); }
 452	OBSOL		5.99 quotactl
 453	STD		{ int|netbsd32||pipe2(netbsd32_intp fildes, int flags); }
-454	COMPAT_110 MODULAR compat_netbsd32_110 \
+454	COMPAT_100 MODULAR compat_netbsd32_100 \
 			{ int|netbsd32||dup3(int from, int to, int flags); }
 455	STD		{ int|netbsd32||kqueue1(int flags); }
 456	STD  		{ int|netbsd32||paccept(int s, \
@@ -1230,5 +1230,5 @@
 			    netbsd32_epoll_eventp_t events, int maxevents, \
 			    netbsd32_timespecp_t timeout, \
 			    netbsd32_sigsetp_t sigmask); }
-505	STD		{ int|netbsd32|110|dup3(int from, int to, \
+505	STD		{ int|netbsd32|100|dup3(int from, int to, \
 			    int flags); }
diff --git a/sys/kern/syscalls.master b/sys/kern/syscalls.master
index bed427e90f75..bd2ee7b51f79 100644
--- a/sys/kern/syscalls.master
+++ b/sys/kern/syscalls.master
@@ -1,4 +1,4 @@
-	$NetBSD: syscalls.master,v 1.312 2024/05/19 22:25:48 christos Exp $
+	$NetBSD: syscalls.master,v 1.313 2024/05/20 01:30:34 christos Exp $
 
 ;	@(#)syscalls.master	8.2 (Berkeley) 1/13/94
 
@@ -954,7 +954,7 @@
 ; 452 only ever appeared in 5.99.x and can be reused after netbsd-7
 452	OBSOL		5.99 quotactl
 453	STD	RUMP	{ int|sys||pipe2(int *fildes, int flags); }
-454	COMPAT_110 MODULAR compat_110 RUMP \
+454	COMPAT_100 MODULAR compat_100 RUMP \
 			{ int|sys||dup3(int from, int to, int flags); }
 455	STD	RUMP	{ int|sys||kqueue1(int flags); }
 456	STD	RUMP	{ int|sys||paccept(int s, struct sockaddr *name, \
@@ -1064,4 +1064,4 @@
 			    struct epoll_event *events, int maxevents, \
 			    const struct timespec *timeout, \
 			    const sigset_t *sigmask); }
-505	STD	RUMP	{ int|sys|110|dup3(int from, int to, int flags); }
+505	STD	RUMP	{ int|sys|100|dup3(int from, int to, int flags); }
diff --git a/sys/modules/compat_110/Makefile b/sys/modules/compat_110/Makefile
index 9c97af9eb299..644173b07e59 100644
--- a/sys/modules/compat_110/Makefile
+++ b/sys/modules/compat_110/Makefile
@@ -1,4 +1,4 @@
-#	$NetBSD: Makefile,v 1.1 2024/05/19 22:25:49 christos Exp $
+#	$NetBSD: Makefile,v 1.2 2024/05/20 01:30:34 christos Exp $
 
 .include "../Makefile.inc"
 
@@ -8,6 +8,6 @@ KMOD=	compat_110
 
 CPPFLAGS+=	-DCOMPAT_110
 
-SRCS+=	compat_110_mod.c sys_decrip_110.c
+SRCS+=	compat_110_mod.c
 
 .include <bsd.kmodule.mk>