diff --git a/sys/amd64/linux/Makefile b/sys/amd64/linux/Makefile
index c8899e662a3a..fc0aac21187d 100644
--- a/sys/amd64/linux/Makefile
+++ b/sys/amd64/linux/Makefile
@@ -9,9 +9,4 @@ sysent:  linux_sysent.c linux_syscall.h linux_proto.h linux_syscalls.c linux_sys
 
 linux_sysent.c linux_syscall.h linux_proto.h linux_syscalls.c linux_systrace_args.c: \
 		../../kern/makesyscalls.sh syscalls.master syscalls.conf
-	-mv -f linux_sysent.c linux_sysent.c.bak
-	-mv -f linux_syscall.h linux_syscall.h.bak
-	-mv -f linux_proto.h linux_proto.h.bak
-	-mv -f linux_syscalls.c linux_syscalls.c.bak
-	-mv -f linux_systrace_args.c linux_systrace_args.c.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
diff --git a/sys/amd64/linux32/Makefile b/sys/amd64/linux32/Makefile
index 482698102888..9219b342af51 100644
--- a/sys/amd64/linux32/Makefile
+++ b/sys/amd64/linux32/Makefile
@@ -9,9 +9,4 @@ sysent:  linux32_sysent.c linux32_syscall.h linux32_proto.h linux32_syscalls.c l
 
 linux32_sysent.c linux32_syscall.h linux32_proto.h linux32_syscalls.c linux32_systrace_args.c: ../../kern/makesyscalls.sh \
 		syscalls.master syscalls.conf
-	-mv -f linux32_sysent.c linux32_sysent.c.bak
-	-mv -f linux32_syscall.h linux32_syscall.h.bak
-	-mv -f linux32_proto.h linux32_proto.h.bak
-	-mv -f linux32_syscalls.c linux32_syscalls.c.bak
-	-mv -f linux32_systrace_args.c linux32_systrace_args.c.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
diff --git a/sys/compat/freebsd32/Makefile b/sys/compat/freebsd32/Makefile
index 34d3e81d122d..777b7355b50e 100644
--- a/sys/compat/freebsd32/Makefile
+++ b/sys/compat/freebsd32/Makefile
@@ -9,11 +9,6 @@ sysent:  freebsd32_sysent.c freebsd32_syscall.h freebsd32_proto.h freebsd32_syst
 
 freebsd32_sysent.c freebsd32_syscalls.c freebsd32_syscall.h freebsd32_proto.h freebsd32_systrace_args.c : \
 	    ../../kern/makesyscalls.sh syscalls.master syscalls.conf
-	-mv -f freebsd32_sysent.c freebsd32_sysent.c.bak
-	-mv -f freebsd32_syscalls.c freebsd32_syscalls.c.bak
-	-mv -f freebsd32_syscall.h freebsd32_syscall.h.bak
-	-mv -f freebsd32_proto.h freebsd32_proto.h.bak
-	-mv -f freebsd32_systrace_args.c  freebsd32_systrace_args.c.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
 
 clean:
diff --git a/sys/compat/svr4/Makefile b/sys/compat/svr4/Makefile
index a90cd555dddb..06cacea1cd5b 100644
--- a/sys/compat/svr4/Makefile
+++ b/sys/compat/svr4/Makefile
@@ -9,9 +9,5 @@ sysent:  svr4_sysent.c svr4_syscall.h svr4_proto.h
 
 svr4_syscallnames.c svr4_sysent.c svr4_syscall.h svr4_proto.h: \
 		../../kern/makesyscalls.sh syscalls.master syscalls.conf
-	-mv -f svr4_syscallnames.c svr4_syscallnames.c.bak
-	-mv -f svr4_sysent.c svr4_sysent.c.bak
-	-mv -f svr4_syscall.h svr4_syscall.h.bak
-	-mv -f svr4_proto.h svr4_proto.h.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
 
diff --git a/sys/i386/ibcs2/Makefile b/sys/i386/ibcs2/Makefile
index 68e91fa17485..1802d6e94b95 100644
--- a/sys/i386/ibcs2/Makefile
+++ b/sys/i386/ibcs2/Makefile
@@ -9,24 +9,16 @@ sysent:  ibcs2_sysent.c ibcs2_syscall.h ibcs2_proto.h
 
 ibcs2_sysent.c ibcs2_syscall.h ibcs2_proto.h: ../../kern/makesyscalls.sh \
 		syscalls.master syscalls.conf
-	-mv -f ibcs2_sysent.c ibcs2_sysent.c.bak
-	-mv -f ibcs2_syscall.h ibcs2_syscall.h.bak
-	-mv -f ibcs2_proto.h ibcs2_proto.h.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
 
 isc_sysent:  ibcs2_isc_sysent.c ibcs2_isc_syscall.h
 
 ibcs2_isc_sysent.c ibcs2_isc_syscall.h : ../../kern/makesyscalls.sh \
 		syscalls.isc syscalls.isc.conf
-	-mv -f ibcs2_isc_sysent.c ibcs2_isc_sysent.c.bak
-	-mv -f ibcs2_isc_syscall.h ibcs2_isc_syscall.h.bak
 	sh ../../kern/makesyscalls.sh syscalls.isc syscalls.isc.conf
 
 xenix_sysent:  ibcs2_xenix_sysent.c ibcs2_xenix_syscall.h ibcs2_xenix.h
 
 ibcs2_xenix_sysent.c ibcs2_xenix_syscall.h ibcs2_xenix.h: \
 		../../kern/makesyscalls.sh syscalls.xenix syscalls.xenix.conf
-	-mv -f ibcs2_xenix_sysent.c ibcs2_xenix_sysent.c.bak
-	-mv -f ibcs2_xenix_syscall.h ibcs2_xenix_syscall.h.bak
-	-mv -f ibcs2_xenix.h ibcs2_xenix.h.bak
 	sh ../../kern/makesyscalls.sh syscalls.xenix syscalls.xenix.conf
diff --git a/sys/i386/linux/Makefile b/sys/i386/linux/Makefile
index c8899e662a3a..fc0aac21187d 100644
--- a/sys/i386/linux/Makefile
+++ b/sys/i386/linux/Makefile
@@ -9,9 +9,4 @@ sysent:  linux_sysent.c linux_syscall.h linux_proto.h linux_syscalls.c linux_sys
 
 linux_sysent.c linux_syscall.h linux_proto.h linux_syscalls.c linux_systrace_args.c: \
 		../../kern/makesyscalls.sh syscalls.master syscalls.conf
-	-mv -f linux_sysent.c linux_sysent.c.bak
-	-mv -f linux_syscall.h linux_syscall.h.bak
-	-mv -f linux_proto.h linux_proto.h.bak
-	-mv -f linux_syscalls.c linux_syscalls.c.bak
-	-mv -f linux_systrace_args.c linux_systrace_args.c.bak
 	sh ../../kern/makesyscalls.sh syscalls.master syscalls.conf
diff --git a/sys/kern/Makefile b/sys/kern/Makefile
index 0721e82f9539..eb11891f63e2 100644
--- a/sys/kern/Makefile
+++ b/sys/kern/Makefile
@@ -12,10 +12,4 @@ sysent: init_sysent.c syscalls.c ../sys/syscall.h ../sys/syscall.mk \
 init_sysent.c syscalls.c systrace_args.c ../sys/syscall.h \
 ../sys/syscall.mk ../sys/sysproto.h: makesyscalls.sh syscalls.master \
 capabilities.conf
-	-mv -f init_sysent.c init_sysent.c.bak
-	-mv -f syscalls.c syscalls.c.bak
-	-mv -f systrace_args.c systrace_args.c.bak
-	-mv -f ../sys/syscall.h ../sys/syscall.h.bak
-	-mv -f ../sys/syscall.mk ../sys/syscall.mk.bak
-	-mv -f ../sys/sysproto.h ../sys/sysproto.h.bak
 	sh makesyscalls.sh syscalls.master