diff --git a/Makefile b/Makefile
index 95572efee5..a7dafa7586 100644
--- a/Makefile
+++ b/Makefile
@@ -335,6 +335,7 @@ LIB_H += builtin.h
 LIB_H += cache.h
 LIB_H += cache-tree.h
 LIB_H += commit.h
+LIB_H += compat/mingw.h
 LIB_H += csum-file.h
 LIB_H += decorate.h
 LIB_H += delta.h
@@ -711,6 +712,33 @@ ifeq ($(uname_S),HP-UX)
 	NO_HSTRERROR = YesPlease
 	NO_SYS_SELECT_H = YesPlease
 endif
+ifneq (,$(findstring MINGW,$(uname_S)))
+	NO_MMAP = YesPlease
+	NO_PREAD = YesPlease
+	NO_OPENSSL = YesPlease
+	NO_CURL = YesPlease
+	NO_SYMLINK_HEAD = YesPlease
+	NO_IPV6 = YesPlease
+	NO_SETENV = YesPlease
+	NO_UNSETENV = YesPlease
+	NO_STRCASESTR = YesPlease
+	NO_STRLCPY = YesPlease
+	NO_MEMMEM = YesPlease
+	NEEDS_LIBICONV = YesPlease
+	OLD_ICONV = YesPlease
+	NO_C99_FORMAT = YesPlease
+	NO_STRTOUMAX = YesPlease
+	NO_MKDTEMP = YesPlease
+	SNPRINTF_RETURNS_BOGUS = YesPlease
+	NO_SVN_TESTS = YesPlease
+	NO_PERL_MAKEMAKER = YesPlease
+	NO_POSIX_ONLY_PROGRAMS = YesPlease
+	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat
+	COMPAT_CFLAGS += -DSNPRINTF_SIZE_CORR=1
+	COMPAT_OBJS += compat/mingw.o compat/fnmatch.o compat/regex.o
+	EXTLIBS += -lws2_32
+	X = .exe
+endif
 ifneq (,$(findstring arm,$(uname_M)))
 	ARM_SHA1 = YesPlease
 endif
diff --git a/compat/mingw.c b/compat/mingw.c
new file mode 100644
index 0000000000..075448d245
--- /dev/null
+++ b/compat/mingw.c
@@ -0,0 +1,57 @@
+#include "../git-compat-util.h"
+
+unsigned int _CRT_fmode = _O_BINARY;
+
+unsigned int sleep (unsigned int seconds)
+{
+	Sleep(seconds*1000);
+	return 0;
+}
+
+int mkstemp(char *template)
+{
+	char *filename = mktemp(template);
+	if (filename == NULL)
+		return -1;
+	return open(filename, O_RDWR | O_CREAT, 0600);
+}
+
+int gettimeofday(struct timeval *tv, void *tz)
+{
+	return -1;
+}
+
+int poll(struct pollfd *ufds, unsigned int nfds, int timeout)
+{
+	return -1;
+}
+
+struct tm *gmtime_r(const time_t *timep, struct tm *result)
+{
+	/* gmtime() in MSVCRT.DLL is thread-safe, but not reentrant */
+	memcpy(result, gmtime(timep), sizeof(struct tm));
+	return result;
+}
+
+struct tm *localtime_r(const time_t *timep, struct tm *result)
+{
+	/* localtime() in MSVCRT.DLL is thread-safe, but not reentrant */
+	memcpy(result, localtime(timep), sizeof(struct tm));
+	return result;
+}
+
+struct passwd *getpwuid(int uid)
+{
+	static struct passwd p;
+	return &p;
+}
+
+int setitimer(int type, struct itimerval *in, struct itimerval *out)
+{
+	return -1;
+}
+
+int sigaction(int sig, struct sigaction *in, struct sigaction *out)
+{
+	return -1;
+}
diff --git a/compat/mingw.h b/compat/mingw.h
new file mode 100644
index 0000000000..e5c0c6ba21
--- /dev/null
+++ b/compat/mingw.h
@@ -0,0 +1,134 @@
+#include <winsock2.h>
+
+/*
+ * things that are not available in header files
+ */
+
+typedef int pid_t;
+#define hstrerror strerror
+
+#define S_IFLNK    0120000 /* Symbolic link */
+#define S_ISLNK(x) (((x) & S_IFMT) == S_IFLNK)
+#define S_ISSOCK(x) 0
+#define S_IRGRP 0
+#define S_IWGRP 0
+#define S_IXGRP 0
+#define S_ISGID 0
+#define S_IROTH 0
+#define S_IXOTH 0
+
+#define WIFEXITED(x) ((unsigned)(x) < 259)	/* STILL_ACTIVE */
+#define WEXITSTATUS(x) ((x) & 0xff)
+#define WIFSIGNALED(x) ((unsigned)(x) > 259)
+
+#define SIGKILL 0
+#define SIGCHLD 0
+#define SIGPIPE 0
+#define SIGHUP 0
+#define SIGQUIT 0
+#define SIGALRM 100
+
+#define F_GETFD 1
+#define F_SETFD 2
+#define FD_CLOEXEC 0x1
+
+struct passwd {
+	char *pw_name;
+	char *pw_gecos;
+	char *pw_dir;
+};
+
+struct pollfd {
+	int fd;           /* file descriptor */
+	short events;     /* requested events */
+	short revents;    /* returned events */
+};
+#define POLLIN 1
+#define POLLHUP 2
+
+typedef void (__cdecl *sig_handler_t)(int);
+struct sigaction {
+	sig_handler_t sa_handler;
+	unsigned sa_flags;
+};
+#define sigemptyset(x) (void)0
+#define SA_RESTART 0
+
+struct itimerval {
+	struct timeval it_value, it_interval;
+};
+#define ITIMER_REAL 0
+
+#define st_blocks st_size/512	/* will be cleaned up later */
+#define lstat stat
+
+/*
+ * trivial stubs
+ */
+
+static inline int readlink(const char *path, char *buf, size_t bufsiz)
+{ errno = ENOSYS; return -1; }
+static inline int symlink(const char *oldpath, const char *newpath)
+{ errno = ENOSYS; return -1; }
+static inline int link(const char *oldpath, const char *newpath)
+{ errno = ENOSYS; return -1; }
+static inline int fchmod(int fildes, mode_t mode)
+{ errno = ENOSYS; return -1; }
+static inline int fork(void)
+{ errno = ENOSYS; return -1; }
+static inline unsigned int alarm(unsigned int seconds)
+{ return 0; }
+static inline int fsync(int fd)
+{ return 0; }
+static inline int getppid(void)
+{ return 1; }
+static inline void sync(void)
+{}
+static inline int getuid()
+{ return 1; }
+static inline struct passwd *getpwnam(const char *name)
+{ return NULL; }
+static inline int fcntl(int fd, int cmd, long arg)
+{
+	if (cmd == F_GETFD || cmd == F_SETFD)
+		return 0;
+	errno = EINVAL;
+	return -1;
+}
+
+/*
+ * simple adaptors
+ */
+
+static inline int mingw_mkdir(const char *path, int mode)
+{
+	return mkdir(path);
+}
+#define mkdir mingw_mkdir
+
+static inline int waitpid(pid_t pid, unsigned *status, unsigned options)
+{
+	if (options == 0)
+		return _cwait(status, pid, 0);
+	errno = EINVAL;
+	return -1;
+}
+
+
+static inline int pipe(int filedes[2])
+{ return _pipe(filedes, 8192, 0); }
+
+/*
+ * implementations of missing functions
+ */
+
+unsigned int sleep (unsigned int seconds);
+int mkstemp(char *template);
+int gettimeofday(struct timeval *tv, void *tz);
+int poll(struct pollfd *ufds, unsigned int nfds, int timeout);
+struct tm *gmtime_r(const time_t *timep, struct tm *result);
+struct tm *localtime_r(const time_t *timep, struct tm *result);
+int getpagesize(void);	/* defined in MinGW's libgcc.a */
+struct passwd *getpwuid(int uid);
+int setitimer(int type, struct itimerval *in, struct itimerval *out);
+int sigaction(int sig, struct sigaction *in, struct sigaction *out);
diff --git a/compat/snprintf.c b/compat/snprintf.c
index dbfc2d6b6e..580966e56a 100644
--- a/compat/snprintf.c
+++ b/compat/snprintf.c
@@ -1,12 +1,25 @@
 #include "../git-compat-util.h"
 
+/*
+ * The size parameter specifies the available space, i.e. includes
+ * the trailing NUL byte; but Windows's vsnprintf expects the
+ * number of characters to write without the trailing NUL.
+ */
+#ifndef SNPRINTF_SIZE_CORR
+#define SNPRINTF_SIZE_CORR 0
+#endif
+
 #undef vsnprintf
 int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
 {
 	char *s;
-	int ret;
+	int ret = -1;
 
-	ret = vsnprintf(str, maxsize, format, ap);
+	if (maxsize > 0) {
+		ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
+		/* Windows does not NUL-terminate if result fills buffer */
+		str[maxsize-1] = 0;
+	}
 	if (ret != -1)
 		return ret;
 
@@ -20,7 +33,7 @@ int git_vsnprintf(char *str, size_t maxsize, const char *format, va_list ap)
 		if (! str)
 			break;
 		s = str;
-		ret = vsnprintf(str, maxsize, format, ap);
+		ret = vsnprintf(str, maxsize-SNPRINTF_SIZE_CORR, format, ap);
 	}
 	free(s);
 	return ret;
diff --git a/git-compat-util.h b/git-compat-util.h
index c04e8baa87..da7249ac1c 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -63,17 +63,18 @@
 #include <sys/time.h>
 #include <time.h>
 #include <signal.h>
-#include <sys/wait.h>
 #include <fnmatch.h>
+#include <assert.h>
+#include <regex.h>
+#include <utime.h>
+#ifndef __MINGW32__
+#include <sys/wait.h>
 #include <sys/poll.h>
 #include <sys/socket.h>
 #include <sys/ioctl.h>
-#include <utime.h>
 #ifndef NO_SYS_SELECT_H
 #include <sys/select.h>
 #endif
-#include <assert.h>
-#include <regex.h>
 #include <netinet/in.h>
 #include <netinet/tcp.h>
 #include <arpa/inet.h>
@@ -89,6 +90,10 @@
 #include <grp.h>
 #define _ALL_SOURCE 1
 #endif
+#else 	/* __MINGW32__ */
+/* pull in Windows compatibility stuff */
+#include "compat/mingw.h"
+#endif	/* __MINGW32__ */
 
 #ifndef NO_ICONV
 #include <iconv.h>