diff --git a/build.sh b/build.sh
index cf0fb38..ed41a10 100755
--- a/build.sh
+++ b/build.sh
@@ -1,3 +1,3 @@
 #!/bin/sh
 
-${CC} -O3 ${CFLAGS} -o sed *.c
+${CC} -O3 ${CFLAGS} -o sed *.c $(pcre2-config --libs-posix)
diff --git a/compat.h b/compat.h
new file mode 100644
index 0000000..2fa7c2d
--- /dev/null
+++ b/compat.h
@@ -0,0 +1,27 @@
+#include <stdarg.h>
+#include <stdio.h>
+#include <string.h>
+
+#ifndef DEFFILEMODE
+#define DEFFILEMODE 0666
+#endif
+
+#ifndef ALLPERMS
+#define ALLPERMS 07777
+#endif
+
+static inline const char *getprogname() {
+    return "sed";
+}
+
+static inline void errc(int status, int code, const char *fmt, ...) {
+    va_list args;
+
+    fprintf(stderr, "error: ");
+    va_start(args, fmt);
+    vfprintf(stderr, fmt, args);
+    va_end(args);
+    fprintf(stderr, ": %s\n", strerror(code));
+
+    exit(status);
+}
diff --git a/compile.c b/compile.c
index 47249c3..774afba 100644
--- a/compile.c
+++ b/compile.c
@@ -33,8 +33,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-
 #include <sys/types.h>
 #include <sys/stat.h>
 
@@ -43,7 +41,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
-#include <regex.h>
+#include <pcre2posix.h>
 #include <stdbool.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -52,6 +50,7 @@
 
 #include "defs.h"
 #include "extern.h"
+#include "compat.h"
 
 #define LHSZ	128
 #define	LHMASK	(LHSZ - 1)
diff --git a/main.c b/main.c
index 59800bd..f4b9875 100644
--- a/main.c
+++ b/main.c
@@ -45,7 +45,7 @@
 #include <libgen.h>
 #include <limits.h>
 #include <locale.h>
-#include <regex.h>
+#include <pcre2posix.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -54,6 +54,7 @@
 
 #include "defs.h"
 #include "extern.h"
+#include "compat.h"
 
 /*
  * Linked list of units (strings and files) to be compiled
@@ -108,7 +109,7 @@ u_long linenum;
 
 static void add_compunit(enum e_cut, char *);
 static void add_file(char *);
-static void usage(void) __dead2;
+static void usage(void);
 
 int
 main(int argc, char *argv[])
diff --git a/misc.c b/misc.c
index 3a1aae7..d3dc420 100644
--- a/misc.c
+++ b/misc.c
@@ -33,13 +33,11 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-
 #include <sys/types.h>
 
 #include <err.h>
 #include <limits.h>
-#include <regex.h>
+#include <pcre2posix.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
diff --git a/process.c b/process.c
index c177524..b9a04e7 100644
--- a/process.c
+++ b/process.c
@@ -33,8 +33,6 @@
  * SUCH DAMAGE.
  */
 
-#include <sys/cdefs.h>
-
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
@@ -45,7 +43,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <limits.h>
-#include <regex.h>
+#include <pcre2posix.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -55,6 +53,7 @@
 
 #include "defs.h"
 #include "extern.h"
+#include "compat.h"
 
 static SPACE HS, PS, SS, YS;
 #define	pd		PS.deleted
diff --git a/sed b/sed
new file mode 100755
index 0000000..b4388d2
Binary files /dev/null and b/sed differ