diff --git a/configure.ac b/configure.ac
index 55fcfe6..1e26c93 100644
--- a/configure.ac
+++ b/configure.ac
@@ -51,15 +51,19 @@ AS_CASE([$host_os],
     AC_SEARCH_LIBS([clock_gettime], [rt], [CLOCK_GETTIME_LIBS="-lrt"])
     AC_SUBST([CLOCK_GETTIME_LIBS])
     LIBS="$saved_LIBS"
+    AM_CONDITIONAL([BUILD_LINK_VERSION_SCRIPT], [1])
   ],
   [*-musl*], [
     # Upstream refuses to define this, we will do it ourselves then.
     AC_DEFINE([__MUSL__], [1], [Define to 1 if we are building for musl])
+    AM_CONDITIONAL([BUILD_LINK_VERSION_SCRIPT], [1])
   ],
-)
+  [
+  AM_CONDITIONAL([BUILD_LINK_VERSION_SCRIPT], [1])
+  ])
 
 # Checks for header files.
-AC_CHECK_HEADERS([sys/ndir.h sys/dir.h ndir.h dirent.h])
+AC_CHECK_HEADERS([sys/ndir.h sys/dir.h ndir.h dirent.h nlist.h])
 
 # Checks for typedefs, structures, and compiler characteristics.
 AC_C_INLINE
@@ -143,7 +147,8 @@ AC_LINK_IFELSE(
 
 AC_CHECK_FUNCS([clearenv dirfd fopencookie __fpurge \
                 getauxval getentropy getexecname getline \
-                pstat_getproc sysconf])
+                pstat_getproc sysconf \
+		strlcpy strlcat strnstr strmode fpurge])
 AM_CONDITIONAL([HAVE_GETENTROPY], [test "x$ac_cv_func_getentropy" = "xtrue"])
 
 AC_CONFIG_FILES([
diff --git a/include/bsd/string.h b/include/bsd/string.h
index f987fee..a1e17ed 100644
--- a/include/bsd/string.h
+++ b/include/bsd/string.h
@@ -41,10 +41,21 @@
 #include <sys/types.h>
 
 __BEGIN_DECLS
+#if !HAVE_STRLCPY
 size_t strlcpy(char *dst, const char *src, size_t siz);
+#endif
+
+#if !HAVE_STRLCAT
 size_t strlcat(char *dst, const char *src, size_t siz);
+#endif
+
+#if !HAVE_STRNSTR
 char *strnstr(const char *str, const char *find, size_t str_len);
+#endif
+
+#if !HAVE_STRMODE
 void strmode(mode_t mode, char *str);
+#endif
 
 #if !defined(__GLIBC__) || \
     (defined(__GLIBC__) && (!__GLIBC_PREREQ(2, 25) || !defined(_GNU_SOURCE)))
diff --git a/src/Makefile.am b/src/Makefile.am
index f3cc0fa..3aaecd4 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -56,8 +56,10 @@ libbsd_la_DEPENDENCIES = \
 libbsd_la_LIBADD = \
 	$(CLOCK_GETTIME_LIBS)
 libbsd_la_LDFLAGS = \
-	-Wl,--version-script=$(srcdir)/libbsd.map \
 	-version-number $(LIBBSD_ABI)
+if BUILD_LINK_VERSION_SCRIPT
+libbsd_la_LDFLAGS += -Wl,--version-script=$(srcdir)/libbsd.map
+endif
 libbsd_la_SOURCES = \
 	arc4random.c \
 	arc4random.h \
diff --git a/src/fpurge.c b/src/fpurge.c
index 462535a..a8941db 100644
--- a/src/fpurge.c
+++ b/src/fpurge.c
@@ -26,9 +26,10 @@
 
 #include <errno.h>
 #include <stdio.h>
-#include <stdio_ext.h>
 
 #ifdef HAVE___FPURGE
+#include <stdio_ext.h>
+
 int
 fpurge(FILE *fp)
 {
@@ -41,6 +42,36 @@ fpurge(FILE *fp)
 
 	return 0;
 }
+/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin 1.7 */
+#elif HAVE_FPURGE
+int
+fpurge(FILE *fp)
+{
+	if (fp == NULL || fileno(fp) < 0) {
+		errno = EBADF;
+		return EOF;
+	}
+
+  /* Call the system's fpurge function.  */
+#undef fpurge
+#if !HAVE_DECL_FPURGE
+  extern int fpurge (FILE *);
+#endif
+  int result = fpurge (fp);
+/* FreeBSD, NetBSD, OpenBSD, DragonFly, Mac OS X, Cygwin */
+#if defined(__sferror) || defined(__DragonFly__)
+  if (result == 0)
+    /* Correct the invariants that fpurge broke.
+       <stdio.h> on BSD systems says:
+         "The following always hold: if _flags & __SRD, _w is 0."
+       If this invariant is not fulfilled and the stream is read-write but
+       currently reading, subsequent putc or fputc calls will write directly
+       into the buffer, although they shouldn't be allowed to.  */
+    if ((fp->_flags & __SRD) != 0)
+      fp->_w = 0;
+#endif
+  return result;
+}
 #else
 #error "Function fpurge() needs to be ported."
 #endif
diff --git a/src/funopen.c b/src/funopen.c
index 1e05c7e..65ba5a8 100644
--- a/src/funopen.c
+++ b/src/funopen.c
@@ -143,6 +143,7 @@ funopen(const void *cookie,
  * they will not add the needed support to implement it. Just ignore this
  * interface there, as it has never been provided anyway.
  */
+#elif defined(__MACH__)
 #else
 #error "Function funopen() needs to be ported or disabled."
 #endif
diff --git a/src/hash/sha512.h b/src/hash/sha512.h
index 4f368a1..7632e25 100644
--- a/src/hash/sha512.h
+++ b/src/hash/sha512.h
@@ -29,7 +29,11 @@
 #ifndef _SHA512_H_
 #define _SHA512_H_
 
+#ifdef __MACH__
+#include <stdint.h>
+#else
 #include <sys/types.h>
+#endif
 
 #define SHA512_DIGEST_LENGTH		64
 
diff --git a/src/hash/sha512c.c b/src/hash/sha512c.c
index b3c8d5e..602f54e 100644
--- a/src/hash/sha512c.c
+++ b/src/hash/sha512c.c
@@ -25,7 +25,12 @@
  */
 
 #include <sys/cdefs.h>
+
+#ifdef __MACH__
+#include <machine/endian.h>
+#else
 #include <sys/endian.h>
+#endif
 #include <sys/types.h>
 
 #include <string.h>
diff --git a/src/local-link.h b/src/local-link.h
index d518dcf..84694a2 100644
--- a/src/local-link.h
+++ b/src/local-link.h
@@ -27,7 +27,11 @@
 #ifndef LIBBSD_LOCAL_LINK_H
 #define LIBBSD_LOCAL_LINK_H
 
+#ifdef __MACH__
+#define libbsd_link_warning(symbol, msg)
+#else
 #define libbsd_link_warning(symbol, msg) \
 	static const char libbsd_emit_link_warning_##symbol[] \
 		__attribute__((used,section(".gnu.warning." #symbol))) = msg;
 #endif
+#endif
diff --git a/src/nlist.c b/src/nlist.c
index 0932f59..4502048 100644
--- a/src/nlist.c
+++ b/src/nlist.c
@@ -41,6 +41,7 @@
 #include <unistd.h>
 #include <nlist.h>
 
+#if !HAVE_NLIST_H
 #include "local-elf.h"
 
 #define SIZE_T_MAX 0xffffffffU
@@ -265,3 +266,4 @@ nlist(const char *name, struct nlist *list)
 	(void)close(fd);
 	return (n);
 }
+#endif
diff --git a/src/readpassphrase.c b/src/readpassphrase.c
index f9f6195..2bc5fb4 100644
--- a/src/readpassphrase.c
+++ b/src/readpassphrase.c
@@ -36,6 +36,14 @@
 #define TCSASOFT 0
 #endif
 
+#ifndef _SIGMAX
+#define	_SIGMAX	64
+#endif
+
+#ifndef _NSIG
+#define _NSIG (_SIGMAX + 1)
+#endif
+
 static volatile sig_atomic_t signo[_NSIG];
 
 static void handler(int);
diff --git a/src/setproctitle.c b/src/setproctitle.c
index 038ac7d..e9ee09c 100644
--- a/src/setproctitle.c
+++ b/src/setproctitle.c
@@ -32,6 +32,10 @@
 #include <unistd.h>
 #include <string.h>
 
+#ifdef __MACH__
+extern char **environ;
+#endif
+
 static struct {
 	/* Original value. */
 	const char *arg0;
@@ -280,16 +284,22 @@ setproctitle_impl(const char *fmt, ...)
 		*++nul = '\0';
 	}
 }
+#ifndef __MACH__
 __asm__(".symver setproctitle_impl,setproctitle@@LIBBSD_0.5");
+#endif
 
 /* The original function introduced in 0.2 was a stub, it only got implemented
  * in 0.5, make the implementation available in the old version as an alias
  * for code linking against that version, and change the default to use the
  * new version, so that new code depends on the implemented version. */
-#ifdef HAVE_TYPEOF
+#ifdef __MACH__
+void setproctitle_stub(const char *fmt, ...);
+#elif HAVE_TYPEOF
 extern typeof(setproctitle_impl) setproctitle_stub __attribute__((alias("setproctitle_impl")));
 #else
 void setproctitle_stub(const char *fmt, ...)
 	__attribute__((alias("setproctitle_impl")));
 #endif
+#ifndef __MACH__
 __asm__(".symver setproctitle_stub,setproctitle@LIBBSD_0.2");
+#endif
diff --git a/src/strlcat.c b/src/strlcat.c
index 14c53a1..5961c17 100644
--- a/src/strlcat.c
+++ b/src/strlcat.c
@@ -26,6 +26,7 @@
  * Returns strlen(src) + MIN(dsize, strlen(initial dst)).
  * If retval >= dsize, truncation occurred.
  */
+#if !HAVE_STRLCAT
 size_t
 strlcat(char *dst, const char *src, size_t dsize)
 {
@@ -53,3 +54,4 @@ strlcat(char *dst, const char *src, size_t dsize)
 
 	return(dlen + (src - osrc));	/* count does not include NUL */
 }
+#endif
diff --git a/src/strlcpy.c b/src/strlcpy.c
index e9a7fe4..5137acb 100644
--- a/src/strlcpy.c
+++ b/src/strlcpy.c
@@ -24,6 +24,7 @@
  * chars will be copied.  Always NUL terminates (unless dsize == 0).
  * Returns strlen(src); if retval >= dsize, truncation occurred.
  */
+#if !HAVE_STRLCPY
 size_t
 strlcpy(char *dst, const char *src, size_t dsize)
 {
@@ -48,3 +49,4 @@ strlcpy(char *dst, const char *src, size_t dsize)
 
 	return(src - osrc - 1);	/* count does not include NUL */
 }
+#endif
diff --git a/src/strmode.c b/src/strmode.c
index e6afde5..da680c9 100644
--- a/src/strmode.c
+++ b/src/strmode.c
@@ -32,6 +32,7 @@
 #include <sys/stat.h>
 #include <string.h>
 
+#if !HAVE_STRMODE
 void
 strmode(mode_t mode, char *p)
 {
@@ -141,3 +142,4 @@ strmode(mode_t mode, char *p)
 	*p++ = ' ';		/* will be a '+' if ACL's implemented */
 	*p = '\0';
 }
+#endif
diff --git a/src/unvis.c b/src/unvis.c
index 94e3e7a..fba4c66 100644
--- a/src/unvis.c
+++ b/src/unvis.c
@@ -565,11 +565,15 @@ strnunvis_openbsd(char *dst, const char *src, size_t dlen)
 {
 	return strnunvisx(dst, dlen, src, 0);
 }
+#ifndef __MACH__
 __asm__(".symver strnunvis_openbsd,strnunvis@@LIBBSD_0.2");
+#endif
 
 int
 strnunvis_netbsd(char *dst, size_t dlen, const char *src)
 {
 	return strnunvisx(dst, dlen, src, 0);
 }
+#ifndef __MACH__
 __asm__(".symver strnunvis_netbsd,strnunvis@LIBBSD_0.9.1");
+#endif
diff --git a/src/vis.c b/src/vis.c
index c2cd2d8..2d84330 100644
--- a/src/vis.c
+++ b/src/vis.c
@@ -723,14 +723,18 @@ strnvis_openbsd(char *mbdst, const char *mbsrc, size_t dlen, int flags)
 {
 	return istrsenvisxl(&mbdst, &dlen, mbsrc, flags, "", NULL);
 }
+#ifndef __MACH__
 __asm__(".symver strnvis_openbsd,strnvis@@LIBBSD_0.2");
+#endif
 
 int
 strnvis_netbsd(char *mbdst, size_t dlen, const char *mbsrc, int flags)
 {
 	return istrsenvisxl(&mbdst, &dlen, mbsrc, flags, "", NULL);
 }
+#ifndef __MACH__
 __asm__(".symver strnvis_netbsd,strnvis@LIBBSD_0.9.1");
+#endif
 
 int
 stravis(char **mbdstp, const char *mbsrc, int flags)