diff -Naur orig/bsdsed-0.99.2/Makefile mod/bsdsed-0.99.2/Makefile
--- a/Makefile	2021-06-27 13:43:27.000000000 -0500
+++ b/Makefile	2026-05-26 02:06:54.688173361 -0500
@@ -4,7 +4,7 @@
 BINDIR  ?= $(PREFIX)/bin
 DATADIR ?= $(PREFIX)/share
 MANDIR  ?= $(DATADIR)/man/man1
-EXTRA_CFLAGS = -Wall -Wextra -I. -Dlint
+EXTRA_CFLAGS = -Wall -Wextra -I. -Dlint -D_XOPEN_SOURCE=700 -D_DEFAULT_SOURCE
 
 OBJS = compile.o main.o misc.o process.o errc.o
 
diff -Naur orig/bsdsed-0.99.2/sys/cdefs.h mod/bsdsed-0.99.2/sys/cdefs.h
--- a/sys/cdefs.h	2021-06-27 13:43:27.000000000 -0500
+++ b/sys/cdefs.h	2026-05-26 02:06:33.401607906 -0500
@@ -1,17 +1,33 @@
 #ifndef CDEFS_H
 #define CDEFS_H
 
+#if defined(__has_include_next)
+#if __has_include_next(<sys/cdefs.h>)
+#include_next <sys/cdefs.h>
+#endif
+#elif defined(__GNUC__)
+#include_next <sys/cdefs.h>
+#endif
+
 #define __FBSDID(x)
 
 /* other compat bits */
 
+#ifndef DEFFILEMODE
 #define	DEFFILEMODE	(S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)
+#endif
+#ifndef ALLPERMS
 #define ALLPERMS (S_ISUID|S_ISGID|S_ISVTX|S_IRWXU|S_IRWXG|S_IRWXO)
+#endif
 
 extern char *__progname;
 
+#ifndef __unreachable
 #define __unreachable()
+#endif
+#ifndef getprogname
 #define getprogname() __progname
+#endif
 
 void errc(int status, int code, const char *format, ...);