diff --git a/configure.ac b/configure.ac
index c26dbb7..66a9e1f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -14,8 +14,8 @@ AM_PROG_CC_C_O
 AC_PROG_CPP
 AC_PROG_LIBTOOL
 
-AC_CHECK_HEADERS(inttypes.h stdint.h getopt.h libc.h malloc.h)
-AC_CHECK_FUNCS(open64 lseek64 mmap64 fopen64 fseeko _IO_getc getline getdelim __getdelim fgetln __srefill map_fd memalign posix_memalign)
+AC_CHECK_HEADERS(inttypes.h stdint.h getopt.h libc.h malloc.h dlfcn.h regex.h sys/socket.h sys/uio.h aio.h sys/mman.h sys/wait.h sys/resource.h)
+AC_CHECK_FUNCS(open64 lseek64 mmap64 fopen64 fseeko _IO_getc getline getdelim __getdelim fgetln __srefill map_fd memalign posix_memalign aio_read accept socket readv pread recv recvfrom recvmsg mmap valloc sigaction)
 AC_CHECK_TYPES(sighandler_t, [], [],
   [#define _GNU_SOURCE
    #include <signal.h>])
@@ -25,6 +25,13 @@ AC_CHECK_TYPES(socklen_t, [], [],
   [#include <sys/types.h>
    #include <sys/socket.h>])
 
+AC_MSG_CHECKING(for read() prototype)
+AC_TRY_COMPILE([#include <unistd.h>],
+ [ssize_t read(int fd, void *buf, size_t count);],
+ [AC_MSG_RESULT(ssize_t read(... size_t);)
+  AC_DEFINE(READ_USES_SSIZE_T, 1, [Define to 1 if read() uses ssize_t.])],
+ [AC_MSG_RESULT(int read(... unsigned int);)])
+
 AC_CHECK_FUNCS(getopt_long,
  [AC_DEFINE(HAVE_GETOPT_LONG, 1, Define to 1 if you have the `getopt_long' function.)],
  [AC_CHECK_LIB(gnugetopt, getopt_long,
diff --git a/src/fd.c b/src/fd.c
index 992ebdd..91bc7ec 100644
--- a/src/fd.c
+++ b/src/fd.c
@@ -25,7 +25,9 @@
 #   include <inttypes.h>
 #endif
 #include <stdlib.h>
-#include <regex.h>
+#if defined HAVE_REGEX_H
+#   include <regex.h>
+#endif
 #include <string.h>
 #include <math.h>
 
@@ -34,8 +36,10 @@
 #include "fd.h"
 
 /* Regex stuff */
+#if defined HAVE_REGEX_H
 static regex_t re_include, re_exclude;
 static int has_include = 0, has_exclude = 0;
+#endif
 
 /* File descriptor stuff. When program is launched, we use the static array of
  * 32 structures, which ought to be enough for most programs. If it happens
@@ -66,14 +70,22 @@ static int     autoinc = 0;
 
 void _zz_include(char const *regex)
 {
+#if defined HAVE_REGEX_H
     if(regcomp(&re_include, regex, REG_EXTENDED) == 0)
         has_include = 1;
+#else
+    (void)regex;
+#endif
 }
 
 void _zz_exclude(char const *regex)
 {
+#if defined HAVE_REGEX_H
     if(regcomp(&re_exclude, regex, REG_EXTENDED) == 0)
         has_exclude = 1;
+#else
+    (void)regex;
+#endif
 }
 
 void _zz_setseed(int32_t s)
@@ -161,11 +173,15 @@ void _zz_fd_fini(void)
 
 int _zz_mustwatch(char const *file)
 {
+#if defined HAVE_REGEX_H
     if(has_include && regexec(&re_include, file, 0, NULL, 0) == REG_NOMATCH)
         return 0; /* not included: ignore */
 
     if(has_exclude && regexec(&re_exclude, file, 0, NULL, 0) != REG_NOMATCH)
         return 0; /* excluded: ignore */
+#else
+    (void)file;
+#endif
 
     return 1; /* default */
 }
@@ -229,7 +245,7 @@ void _zz_register(int fd)
     files[i].fuzz.seed = seed;
     files[i].fuzz.ratio = _zz_getratio();
     files[i].fuzz.cur = -1;
-#ifdef HAVE_FGETLN
+#if defined HAVE_FGETLN
     files[i].fuzz.tmp = NULL;
 #endif
 
@@ -245,7 +261,7 @@ void _zz_unregister(int fd)
         return;
 
     files[fds[fd]].managed = 0;
-#ifdef HAVE_FGETLN
+#if defined HAVE_FGETLN
     if(files[fds[fd]].fuzz.tmp)
         free(files[fds[fd]].fuzz.tmp);
 #endif
diff --git a/src/lib-fd.c b/src/lib-fd.c
index b1f5496..d4643a1 100644
--- a/src/lib-fd.c
+++ b/src/lib-fd.c
@@ -33,15 +33,21 @@
 #endif
 #include <stdlib.h>
 #include <string.h>
-#include <dlfcn.h>
+#include <stdio.h>
 
 #include <sys/types.h>
-#include <sys/socket.h>
-#include <sys/uio.h>
+#if defined HAVE_SYS_SOCKET_H
+#   include <sys/socket.h>
+#endif
+#if defined HAVE_SYS_UIO_H
+#   include <sys/uio.h>
+#endif
 #include <unistd.h>
 #include <fcntl.h>
 #include <stdarg.h>
-#include <aio.h>
+#if defined HAVE_AIO_H
+#   include <aio.h>
+#endif
 
 #include "libzzuf.h"
 #include "lib-load.h"
@@ -49,35 +55,57 @@
 #include "fuzz.h"
 #include "fd.h"
 
-#ifdef HAVE_SOCKLEN_T
+#if defined HAVE_SOCKLEN_T
 #   define SOCKLEN_T socklen_t
 #else
 #   define SOCKLEN_T int
 #endif
 
 /* Local prototypes */
+#if defined HAVE_READV || defined HAVE_RECVMSG
 static void fuzz_iovec   (int fd, const struct iovec *iov, ssize_t ret);
+#endif
 static void offset_check (int fd);
 
 /* Library functions that we divert */
 static int     (*open_orig)    (const char *file, int oflag, ...);
-#ifdef HAVE_OPEN64
+#if defined HAVE_OPEN64
 static int     (*open64_orig)  (const char *file, int oflag, ...);
 #endif
+#if defined HAVE_ACCEPT
 static int     (*accept_orig)  (int sockfd, struct sockaddr *addr,
                                 SOCKLEN_T *addrlen);
+#endif
+#if defined HAVE_SOCKET
 static int     (*socket_orig)  (int domain, int type, int protocol);
+#endif
+#if defined HAVE_RECV
 static int     (*recv_orig)    (int s, void *buf, size_t len, int flags);
+#endif
+#if defined HAVE_RECVFROM
 static int     (*recvfrom_orig)(int s, void *buf, size_t len, int flags,
                                 struct sockaddr *from, SOCKLEN_T *fromlen);
+#endif
+#if defined HAVE_RECVMSG
 static int     (*recvmsg_orig) (int s,  struct msghdr *hdr, int flags);
+#endif
+#if defined READ_USES_SSIZE_T
 static ssize_t (*read_orig)    (int fd, void *buf, size_t count);
+#else
+static int     (*read_orig)    (int fd, void *buf, unsigned int count);
+#endif
+#if defined HAVE_READV
 static ssize_t (*readv_orig)   (int fd, const struct iovec *iov, int count);
+#endif
+#if defined HAVE_PREAD
 static ssize_t (*pread_orig)   (int fd, void *buf, size_t count, off_t offset);
+#endif
+#if defined HAVE_AIO_READ
 static int     (*aio_read_orig)   (struct aiocb *aiocbp);
 static ssize_t (*aio_return_orig) (struct aiocb *aiocbp);
+#endif
 static off_t   (*lseek_orig)   (int fd, off_t offset, int whence);
-#ifdef HAVE_LSEEK64
+#if defined HAVE_LSEEK64
 static off64_t (*lseek64_orig) (int fd, off64_t offset, int whence);
 #endif
 static int     (*close_orig)   (int fd);
@@ -119,13 +147,14 @@ int open(const char *file, int oflag, ...)
     int ret; OPEN(open); return ret;
 }
 
-#ifdef HAVE_OPEN64
+#if defined HAVE_OPEN64
 int open64(const char *file, int oflag, ...)
 {
     int ret; OPEN(open64); return ret;
 }
 #endif
 
+#if defined HAVE_ACCEPT
 int accept(int sockfd, struct sockaddr *addr, SOCKLEN_T *addrlen)
 {
     int ret;
@@ -143,7 +172,9 @@ int accept(int sockfd, struct sockaddr *addr, SOCKLEN_T *addrlen)
 
     return ret;
 }
+#endif
 
+#if defined HAVE_SOCKET
 int socket(int domain, int type, int protocol)
 {
     int ret;
@@ -161,7 +192,9 @@ int socket(int domain, int type, int protocol)
 
     return ret;
 }
+#endif
 
+#if defined HAVE_RECV
 int recv(int s, void *buf, size_t len, int flags)
 {
     int ret;
@@ -191,7 +224,9 @@ int recv(int s, void *buf, size_t len, int flags)
 
     return ret;
 }
+#endif
 
+#if defined HAVE_RECVFROM
 int recvfrom(int s, void *buf, size_t len, int flags,
              struct sockaddr *from, SOCKLEN_T *fromlen) 
 {
@@ -223,7 +258,9 @@ int recvfrom(int s, void *buf, size_t len, int flags,
 
     return ret;
 }
+#endif
 
+#if defined HAVE_RECVMSG
 int recvmsg(int s, struct msghdr *hdr, int flags)
 {
     ssize_t ret;
@@ -238,8 +275,13 @@ int recvmsg(int s, struct msghdr *hdr, int flags)
 
     return ret;
 }
+#endif
 
+#if defined READ_USES_SSIZE_T
 ssize_t read(int fd, void *buf, size_t count)
+#else
+int read(int fd, void *buf, unsigned int count)
+#endif
 {
     int ret;
 
@@ -269,6 +311,7 @@ ssize_t read(int fd, void *buf, size_t count)
     return ret;
 }
 
+#if defined HAVE_READV
 ssize_t readv(int fd, const struct iovec *iov, int count)
 {
     ssize_t ret;
@@ -284,7 +327,9 @@ ssize_t readv(int fd, const struct iovec *iov, int count)
     offset_check(fd);
     return ret;
 }
+#endif
 
+#if defined HAVE_PREAD
 ssize_t pread(int fd, void *buf, size_t count, off_t offset)
 {
     int ret;
@@ -317,6 +362,7 @@ ssize_t pread(int fd, void *buf, size_t count, off_t offset)
 
     return ret;
 }
+#endif
 
 #define LSEEK(fn, off_t) \
     do \
@@ -338,7 +384,7 @@ off_t lseek(int fd, off_t offset, int whence)
     return ret;
 }
 
-#ifdef HAVE_LSEEK64
+#if defined HAVE_LSEEK64
 off64_t lseek64(int fd, off64_t offset, int whence)
 {
     off64_t ret;
@@ -347,6 +393,7 @@ off64_t lseek64(int fd, off64_t offset, int whence)
 }
 #endif
 
+#if defined HAVE_AIO_READ
 int aio_read(struct aiocb *aiocbp)
 {
     int ret;
@@ -393,6 +440,7 @@ ssize_t aio_return(struct aiocb *aiocbp)
 
     return ret;
 }
+#endif
 
 int close(int fd)
 {
@@ -415,6 +463,7 @@ int close(int fd)
 
 /* XXX: the following functions are local */
 
+#if defined HAVE_READV || defined HAVE_RECVMSG
 static void fuzz_iovec(int fd, const struct iovec *iov, ssize_t ret)
 {
     /* NOTE: We assume that iov countains at least <ret> bytes. */
@@ -433,11 +482,12 @@ static void fuzz_iovec(int fd, const struct iovec *iov, ssize_t ret)
         ret -= len;
     }
 }
+#endif
 
 static void offset_check(int fd)
 {
     /* Sanity check, can be OK though (for instance with a character device) */
-#ifdef HAVE_LSEEK64
+#if defined HAVE_LSEEK64
     off64_t ret;
     LOADSYM(lseek64);
     ret = lseek64_orig(fd, 0, SEEK_CUR);
diff --git a/src/lib-load.h b/src/lib-load.h
index 61506b0..bf41d21 100644
--- a/src/lib-load.h
+++ b/src/lib-load.h
@@ -29,11 +29,21 @@
 #define STR(x) #x
 #define ORIG(x) x##_orig
 
-#define LOADSYM(x) \
-    do { \
-        if(!ORIG(x)) \
-            ORIG(x) = dlsym(RTLD_NEXT, STR(x)); \
-        if(!ORIG(x)) \
-            abort(); \
-    } while(0)
+/* TODO: do the Win32 part */
+#ifdef HAVE_DLFCN_H
+#   include <dlfcn.h>
+#   define LOADSYM(x) \
+        do { \
+            if(!ORIG(x)) \
+                ORIG(x) = dlsym(RTLD_NEXT, STR(x)); \
+            if(!ORIG(x)) \
+                abort(); \
+        } while(0)
+#else
+#   define LOADSYM(x) \
+        do { \
+            if(!ORIG(x)) \
+                abort(); \
+        } while(0)
+#endif
 
diff --git a/src/lib-mem.c b/src/lib-mem.c
index bbf157a..23a0111 100644
--- a/src/lib-mem.c
+++ b/src/lib-mem.c
@@ -34,7 +34,6 @@
 #endif
 #include <stdlib.h>
 #include <string.h>
-#include <dlfcn.h>
 #include <errno.h>
 #include <signal.h>
 
@@ -42,7 +41,9 @@
 #   include <malloc.h>
 #endif
 #include <unistd.h>
-#include <sys/mman.h>
+#if defined HAVE_SYS_MMAN_H
+#   include <sys/mman.h>
+#endif
 #if defined HAVE_LIBC_H
 #   include <libc.h>
 #endif
@@ -53,30 +54,40 @@
 #include "fuzz.h"
 #include "fd.h"
 
+#if !defined SIGKILL
+#   define SIGKILL 9
+#endif
+
 /* TODO: mremap, maybe brk/sbrk (haha) */
 
 /* Library functions that we divert */
 static void *  (*calloc_orig)   (size_t nmemb, size_t size);
 static void *  (*malloc_orig)   (size_t size);
 static void    (*free_orig)     (void *ptr);
+#if defined HAVE_VALLOC
 static void *  (*valloc_orig)   (size_t size);
-#ifdef HAVE_MEMALIGN
+#endif
+#if defined HAVE_MEMALIGN
 static void *  (*memalign_orig) (size_t boundary, size_t size);
 #endif
-#ifdef HAVE_POSIX_MEMALIGN
+#if defined HAVE_POSIX_MEMALIGN
 static int     (*posix_memalign_orig) (void **memptr, size_t alignment,
                                        size_t size);
 #endif
 static void *  (*realloc_orig)  (void *ptr, size_t size);
 
+#if defined HAVE_MMAP
 static void *  (*mmap_orig)     (void *start, size_t length, int prot,
                                  int flags, int fd, off_t offset);
-#ifdef HAVE_MMAP64
+#endif
+#if defined HAVE_MMAP64
 static void *  (*mmap64_orig)   (void *start, size_t length, int prot,
                                  int flags, int fd, off64_t offset);
 #endif
+#if defined HAVE_MUNMAP
 static int     (*munmap_orig)   (void *start, size_t length);
-#ifdef HAVE_MAP_FD
+#endif
+#if defined HAVE_MAP_FD
 static kern_return_t (*map_fd_orig) (int fd, vm_offset_t offset,
                                      vm_offset_t *addr, boolean_t find_space,
                                      vm_size_t numbytes);
@@ -147,6 +158,7 @@ void *realloc(void *ptr, size_t size)
     return ret;
 }
 
+#if defined HAVE_VALLOC
 void *valloc(size_t size)
 {
     void *ret;
@@ -156,8 +168,9 @@ void *valloc(size_t size)
         raise(SIGKILL);
     return ret;
 }
+#endif
 
-#ifdef HAVE_MEMALIGN
+#if defined HAVE_MEMALIGN
 void *memalign(size_t boundary, size_t size)
 {
     void *ret;
@@ -169,7 +182,7 @@ void *memalign(size_t boundary, size_t size)
 }
 #endif
 
-#ifdef HAVE_POSIX_MEMALIGN
+#if defined HAVE_POSIX_MEMALIGN
 int posix_memalign(void **memptr, size_t alignment, size_t size)
 {
     int ret;
@@ -226,13 +239,15 @@ int nbmaps = 0;
                   (long long int)offset, ret); \
     } while(0)
 
+#if defined HAVE_MMAP
 void *mmap(void *start, size_t length, int prot, int flags,
            int fd, off_t offset)
 {
     void *ret; MMAP(mmap, off_t); return ret;
 }
+#endif
 
-#ifdef HAVE_MMAP64
+#if defined HAVE_MMAP64
 void *mmap64(void *start, size_t length, int prot, int flags,
              int fd, off64_t offset)
 {
@@ -240,6 +255,7 @@ void *mmap64(void *start, size_t length, int prot, int flags,
 }
 #endif
 
+#if defined HAVE_MUNMAP
 int munmap(void *start, size_t length)
 {
     int ret, i;
@@ -260,8 +276,9 @@ int munmap(void *start, size_t length)
 
     return munmap_orig(start, length);
 }
+#endif
 
-#ifdef HAVE_MAP_FD
+#if defined HAVE_MAP_FD
 kern_return_t map_fd(int fd, vm_offset_t offset, vm_offset_t *addr,
                      boolean_t find_space, vm_size_t numbytes)
 {
diff --git a/src/lib-signal.c b/src/lib-signal.c
index 2fbe91f..d5fa4af 100644
--- a/src/lib-signal.c
+++ b/src/lib-signal.c
@@ -27,7 +27,6 @@
 #   include <inttypes.h>
 #endif
 #include <stdlib.h>
-#include <dlfcn.h>
 
 #include <string.h>
 #include <signal.h>
@@ -47,8 +46,10 @@
 
 /* Library functions that we divert */
 static SIG_T (*signal_orig)    (int signum, SIG_T handler);
+#if defined HAVE_SIGACTION
 static int   (*sigaction_orig) (int signum, const struct sigaction *act,
                                 struct sigaction *oldact);
+#endif
 /* Local functions */
 static int isfatal(int signum);
 
@@ -59,22 +60,26 @@ static int isfatal(int signum)
         case SIGABRT:
         case SIGFPE:
         case SIGILL:
+#if defined SIGQUIT
         case SIGQUIT:
+#endif
         case SIGSEGV:
+#if defined SIGTRAP
         case SIGTRAP:
-#ifdef SIGSYS
+#endif
+#if defined SIGSYS
         case SIGSYS:
 #endif
-#ifdef SIGEMT
+#if defined SIGEMT
         case SIGEMT:
 #endif
-#ifdef SIGBUS
+#if defined SIGBUS
         case SIGBUS:
 #endif
-#ifdef SIGXCPU
+#if defined SIGXCPU
         case SIGXCPU:
 #endif
-#ifdef SIGXFSZ
+#if defined SIGXFSZ
         case SIGXFSZ:
 #endif
             return 1;
@@ -99,6 +104,7 @@ SIG_T signal(int signum, SIG_T handler)
     return ret;
 }
 
+#if defined HAVE_SIGACTION
 int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 {
     int ret;
@@ -122,4 +128,5 @@ int sigaction(int signum, const struct sigaction *act, struct sigaction *oldact)
 
     return ret;
 }
+#endif
 
diff --git a/src/lib-stream.c b/src/lib-stream.c
index 299be5b..54c4cfd 100644
--- a/src/lib-stream.c
+++ b/src/lib-stream.c
@@ -26,11 +26,10 @@
 #   include <inttypes.h>
 #endif
 #include <stdlib.h>
-#include <dlfcn.h>
 
 #include <stdio.h>
 #include <sys/types.h>
-#ifdef HAVE___SREFILL
+#if defined HAVE___SREFILL
 #   include <unistd.h> /* Needed for __srefill’s lseek() call */
 #endif
 
@@ -40,19 +39,19 @@
 #include "fuzz.h"
 #include "fd.h"
 
-#ifdef HAVE___SREFILL
+#if defined HAVE___SREFILL
 int __srefill(FILE *fp);
 #endif
 
 /* Library functions that we divert */
 static FILE *  (*fopen_orig)    (const char *path, const char *mode);
-#ifdef HAVE_FOPEN64
+#if defined HAVE_FOPEN64
 static FILE *  (*fopen64_orig)  (const char *path, const char *mode);
 #endif
 static FILE *  (*freopen_orig)  (const char *path, const char *mode,
                                  FILE *stream);
 static int     (*fseek_orig)    (FILE *stream, long offset, int whence);
-#ifdef HAVE_FSEEKO
+#if defined HAVE_FSEEKO
 static int     (*fseeko_orig)   (FILE *stream, off_t offset, int whence);
 #endif
 static void    (*rewind_orig)   (FILE *stream);
@@ -60,7 +59,7 @@ static size_t  (*fread_orig)    (void *ptr, size_t size, size_t nmemb,
                                  FILE *stream);
 static int     (*getc_orig)     (FILE *stream);
 static int     (*fgetc_orig)    (FILE *stream);
-#ifdef HAVE__IO_GETC
+#if defined HAVE__IO_GETC
 static int     (*_IO_getc_orig) (FILE *stream);
 #endif
 static char *  (*fgets_orig)    (char *s, int size, FILE *stream);
@@ -68,23 +67,23 @@ static int     (*ungetc_orig)   (int c, FILE *stream);
 static int     (*fclose_orig)   (FILE *fp);
 
 /* Additional GNUisms */
-#ifdef HAVE_GETLINE
+#if defined HAVE_GETLINE
 static ssize_t (*getline_orig)    (char **lineptr, size_t *n, FILE *stream);
 #endif
-#ifdef HAVE_GETDELIM
+#if defined HAVE_GETDELIM
 static ssize_t (*getdelim_orig)   (char **lineptr, size_t *n, int delim,
                                    FILE *stream);
 #endif
-#ifdef HAVE___GETDELIM
+#if defined HAVE___GETDELIM
 static ssize_t (*__getdelim_orig) (char **lineptr, size_t *n, int delim,
                                    FILE *stream);
 #endif
 
 /* Additional BSDisms */
-#ifdef HAVE_FGETLN
+#if defined HAVE_FGETLN
 static char *  (*fgetln_orig)    (FILE *stream, size_t *len);
 #endif
-#ifdef HAVE___SREFILL
+#if defined HAVE___SREFILL
 int            (*__srefill_orig) (FILE *fp);
 #endif
 
@@ -111,7 +110,7 @@ FILE *fopen(const char *path, const char *mode)
     FILE *ret; FOPEN(fopen); return ret;
 }
 
-#ifdef HAVE_FOPEN64
+#if defined HAVE_FOPEN64
 FILE *fopen64(const char *path, const char *mode)
 {
     FILE *ret; FOPEN(fopen64); return ret;
@@ -191,7 +190,7 @@ int fseek(FILE *stream, long offset, int whence)
     int ret; FSEEK(fseek, ftell); return ret;
 }
 
-#ifdef HAVE_FSEEKO
+#if defined HAVE_FSEEKO
 int fseeko(FILE *stream, off_t offset, int whence)
 {
     int ret; FSEEK(fseeko, ftello); return ret;
@@ -301,7 +300,7 @@ int fgetc(FILE *stream)
     int ret; FGETC(fgetc); return ret;
 }
 
-#ifdef HAVE__IO_GETC
+#if defined HAVE__IO_GETC
 int _IO_getc(FILE *stream)
 {
     int ret; FGETC(_IO_getc); return ret;
@@ -468,28 +467,28 @@ int fclose(FILE *fp)
         return ret; \
     } while(0)
 
-#ifdef HAVE_GETLINE
+#if defined HAVE_GETLINE
 ssize_t getline(char **lineptr, size_t *n, FILE *stream)
 {
     ssize_t ret; GETDELIM(getline, '\n', 0); return ret;
 }
 #endif
 
-#ifdef HAVE_GETDELIM
+#if defined HAVE_GETDELIM
 ssize_t getdelim(char **lineptr, size_t *n, int delim, FILE *stream)
 {
     ssize_t ret; GETDELIM(getdelim, delim, 1); return ret;
 }
 #endif
 
-#ifdef HAVE___GETDELIM
+#if defined HAVE___GETDELIM
 ssize_t __getdelim(char **lineptr, size_t *n, int delim, FILE *stream)
 {
     ssize_t ret; GETDELIM(__getdelim, delim, 1); return ret;
 }
 #endif
 
-#ifdef HAVE_FGETLN
+#if defined HAVE_FGETLN
 char *fgetln(FILE *stream, size_t *len)
 {
     char *ret;
@@ -544,7 +543,7 @@ char *fgetln(FILE *stream, size_t *len)
 }
 #endif
 
-#ifdef HAVE___SREFILL
+#if defined HAVE___SREFILL
 int __srefill(FILE *fp)
 {
     off_t newpos;
diff --git a/src/libzzuf.c b/src/libzzuf.c
index bc7e660..057713a 100644
--- a/src/libzzuf.c
+++ b/src/libzzuf.c
@@ -32,7 +32,6 @@
 #include <fcntl.h>
 
 #include <stdarg.h>
-#include <dlfcn.h>
 
 #include "libzzuf.h"
 #include "debug.h"
diff --git a/src/zzuf.c b/src/zzuf.c
index cd9e07a..f9a055f 100644
--- a/src/zzuf.c
+++ b/src/zzuf.c
@@ -23,19 +23,25 @@
 #elif defined HAVE_INTTYPES_H
 #   include <inttypes.h>
 #endif
-#if defined(HAVE_GETOPT_H)
+#if defined HAVE_GETOPT_H
 #   include <getopt.h>
 #endif
 #include <stdio.h>
 #include <stdlib.h>
 #include <unistd.h>
-#include <regex.h>
+#if defined HAVE_REGEX_H
+#   include <regex.h>
+#endif
 #include <string.h>
 #include <errno.h>
 #include <signal.h>
-#include <sys/wait.h>
+#if defined HAVE_SYS_WAIT_H
+#   include <sys/wait.h>
+#endif
 #include <sys/time.h>
-#include <sys/resource.h>
+#if defined HAVE_SYS_RESOURCE_H
+#   include <sys/resource.h>
+#endif
 
 #include "libzzuf.h"
 #include "opts.h"
@@ -45,6 +51,10 @@
 #include "md5.h"
 #include "timer.h"
 
+#if !defined SIGKILL
+#   define SIGKILL 9
+#endif
+
 static void loop_stdin(struct opts *opts);
 
 static void spawn_children(struct opts *opts);
@@ -52,11 +62,13 @@ static void clean_children(struct opts *opts);
 static void read_children(struct opts *opts);
 
 static char const *sig2str(int);
+#if defined HAVE_REGEX_H
 static char *merge_regex(char *, char *);
 static char *merge_file(char *, char *);
+#endif
 static void set_environment(char const *);
 static void version(void);
-#if defined(HAVE_GETOPT_H)
+#if defined HAVE_GETOPT_H
 static void usage(void);
 #endif
 
@@ -74,18 +86,24 @@ static void usage(void);
 int main(int argc, char *argv[])
 {
     struct opts _opts, *opts = &_opts;
-    char *tmp, *include, *exclude;
-    int i, cmdline = 0;
-
-    include = exclude = NULL;
+    char *tmp;
+#if defined HAVE_REGEX_H
+    char *include = NULL, *exclude = NULL;
+    int cmdline = 0;
+#endif
+    int i;
 
     _zz_opts_init(opts);
 
-#if defined(HAVE_GETOPT_H)
+#if defined HAVE_GETOPT_H
     for(;;)
     {
-#   define OPTSTR "AB:cC:dD:E:F:iI:mM:nP:qr:R:s:ST:vxhV"
-#   ifdef HAVE_GETOPT_LONG
+#   if defined HAVE_REGEX_H
+#       define OPTSTR "AB:cC:dD:E:F:iI:mM:nP:qr:R:s:ST:vxhV"
+#   else
+#       define OPTSTR "AB:C:dD:F:imM:nP:qr:R:s:ST:vxhV"
+#   endif
+#   if defined HAVE_GETOPT_LONG
 #       define MOREINFO "Try `%s --help' for more information.\n"
         int option_index = 0;
         static struct option long_options[] =
@@ -93,14 +111,20 @@ int main(int argc, char *argv[])
             /* Long option, needs arg, flag, short option */
             { "autoinc",     0, NULL, 'A' },
             { "max-bytes",   1, NULL, 'B' },
+#if defined HAVE_REGEX_H
             { "cmdline",     0, NULL, 'c' },
+#endif
             { "max-crashes", 1, NULL, 'C' },
             { "debug",       0, NULL, 'd' },
             { "delay",       1, NULL, 'D' },
+#if defined HAVE_REGEX_H
             { "exclude",     1, NULL, 'E' },
+#endif
             { "max-forks",   1, NULL, 'F' },
             { "stdin",       0, NULL, 'i' },
+#if defined HAVE_REGEX_H
             { "include",     1, NULL, 'I' },
+#endif
             { "md5",         0, NULL, 'm' },
             { "max-memory",  1, NULL, 'M' },
             { "network",     0, NULL, 'n' },
@@ -133,9 +157,11 @@ int main(int argc, char *argv[])
         case 'B': /* --max-bytes */
             opts->maxbytes = atoi(optarg);
             break;
+#if defined HAVE_REGEX_H
         case 'c': /* --cmdline */
             cmdline = 1;
             break;
+#endif
         case 'C': /* --max-crashes */
             opts->maxcrashes = atoi(optarg);
             if(opts->maxcrashes <= 0)
@@ -147,6 +173,7 @@ int main(int argc, char *argv[])
         case 'D': /* --delay */
             opts->delay = (int64_t)(atof(optarg) * 1000000.0);
             break;
+#if defined HAVE_REGEX_H
         case 'E': /* --exclude */
             exclude = merge_regex(exclude, optarg);
             if(!exclude)
@@ -156,12 +183,14 @@ int main(int argc, char *argv[])
                 return EXIT_FAILURE;
             }
             break;
+#endif
         case 'F': /* --max-forks */
             opts->maxchild = atoi(optarg) > 1 ? atoi(optarg) : 1;
             break;
         case 'i': /* --stdin */
             setenv("ZZUF_STDIN", "1", 1);
             break;
+#if defined HAVE_REGEX_H
         case 'I': /* --include */
             include = merge_regex(include, optarg);
             if(!include)
@@ -171,6 +200,7 @@ int main(int argc, char *argv[])
                 return EXIT_FAILURE;
             }
             break;
+#endif
         case 'm': /* --md5 */
             opts->md5 = 1;
             break;
@@ -254,6 +284,7 @@ int main(int argc, char *argv[])
     }
 
     /* If asked to launch programs */
+#if defined HAVE_REGEX_H
     if(cmdline)
     {
         int dashdash = 0;
@@ -273,6 +304,8 @@ int main(int argc, char *argv[])
         setenv("ZZUF_INCLUDE", include, 1);
     if(exclude)
         setenv("ZZUF_EXCLUDE", exclude, 1);
+#endif
+
     if(opts->protect)
         setenv("ZZUF_PROTECT", opts->protect, 1);
     if(opts->refuse)
@@ -370,6 +403,7 @@ static void loop_stdin(struct opts *opts)
     _zz_fd_fini();
 }
 
+#if defined HAVE_REGEX_H
 static char *merge_file(char *regex, char *file)
 {
     char *newfile = malloc(5 + 2 * strlen(file) + 1 + 1), *tmp = newfile;
@@ -417,6 +451,7 @@ static char *merge_regex(char *regex, char *string)
 
     return regex;
 }
+#endif
 
 static void spawn_children(struct opts *opts)
 {
@@ -769,14 +804,21 @@ static void version(void)
     printf("Written by Sam Hocevar. Report bugs to <sam@zoy.org>.\n");
 }
 
-#if defined(HAVE_GETOPT_H)
+#if defined HAVE_GETOPT_H
 static void usage(void)
 {
+#if defined HAVE_REGEX_H
     printf("Usage: zzuf [-AcdimnqSvx] [-r ratio] [-s seed | -s start:stop]\n");
     printf("                          [-D delay] [-F forks] [-C crashes] [-B bytes]\n");
     printf("                          [-T seconds] [-M bytes] [-P protect] [-R refuse]\n");
     printf("                          [-I include] [-E exclude] [PROGRAM [--] [ARGS]...]\n");
-#   ifdef HAVE_GETOPT_LONG
+#else
+    printf("Usage: zzuf [-AdimnqSvx] [-r ratio] [-s seed | -s start:stop]\n");
+    printf("                         [-D delay] [-F forks] [-C crashes] [-B bytes]\n");
+    printf("                         [-T seconds] [-M bytes] [-P protect] [-R refuse]\n");
+    printf("                         [PROGRAM [--] [ARGS]...]\n");
+#endif
+#   if defined HAVE_GETOPT_LONG
     printf("       zzuf -h | --help\n");
     printf("       zzuf -V | --version\n");
 #   else
@@ -786,17 +828,23 @@ static void usage(void)
     printf("Run PROGRAM with optional arguments ARGS and fuzz its input.\n");
     printf("\n");
     printf("Mandatory arguments to long options are mandatory for short options too.\n");
-#   ifdef HAVE_GETOPT_LONG
+#   if defined HAVE_GETOPT_LONG
     printf("  -A, --autoinc             increment seed each time a new file is opened\n");
     printf("  -B, --max-bytes <n>       kill children that output more than <n> bytes\n");
+#if defined HAVE_REGEX_H
     printf("  -c, --cmdline             only fuzz files specified in the command line\n");
+#endif
     printf("  -C, --max-crashes <n>     stop after <n> children have crashed (default 1)\n");
     printf("  -d, --debug               print debug messages\n");
     printf("  -D, --delay               delay between forks\n");
+#if defined HAVE_REGEX_H
     printf("  -E, --exclude <regex>     do not fuzz files matching <regex>\n");
+#endif
     printf("  -F, --max-forks <n>       number of concurrent children (default 1)\n");
     printf("  -i, --stdin               fuzz standard input\n");
+#if defined HAVE_REGEX_H
     printf("  -I, --include <regex>     only fuzz files matching <regex>\n");
+#endif
     printf("  -m, --md5                 compute the output's MD5 hash\n");
     printf("  -M, --max-memory <n>      maximum child virtual memory size in MB\n");
     printf("  -n, --network             fuzz network input\n");
@@ -816,14 +864,20 @@ static void usage(void)
 #   else
     printf("  -A               increment seed each time a new file is opened\n");
     printf("  -B <n>           kill children that output more than <n> bytes\n");
+#if defined HAVE_REGEX_H
     printf("  -c               only fuzz files specified in the command line\n");
+#endif
     printf("  -C <n>           stop after <n> children have crashed (default 1)\n");
     printf("  -d               print debug messages\n");
     printf("  -D               delay between forks\n");
+#if defined HAVE_REGEX_H
     printf("  -E <regex>       do not fuzz files matching <regex>\n");
+#endif
     printf("  -F <n>           number of concurrent forks (default 1)\n");
     printf("  -i               fuzz standard input\n");
+#if defined HAVE_REGEX_H
     printf("  -I <regex>       only fuzz files matching <regex>\n");
+#endif
     printf("  -m               compute the output's MD5 hash\n");
     printf("  -M               maximum child virtual memory size in MB\n");
     printf("  -n               fuzz network input\n");