diff --git a/Makefile b/Makefile
index b96c2b316f..aae3b09411 100644
--- a/Makefile
+++ b/Makefile
@@ -784,7 +784,6 @@ ifneq (,$(findstring CYGWIN,$(uname_S)))
 	COMPAT_OBJS += compat/cygwin.o
 endif
 ifneq (,$(findstring MINGW,$(uname_S)))
-	NO_MMAP = YesPlease
 	NO_PREAD = YesPlease
 	NO_OPENSSL = YesPlease
 	NO_CURL = YesPlease
@@ -808,6 +807,7 @@ ifneq (,$(findstring MINGW,$(uname_S)))
 	NO_POSIX_ONLY_PROGRAMS = YesPlease
 	NO_ST_BLOCKS_IN_STRUCT_STAT = YesPlease
 	NO_NSEC = YesPlease
+	USE_WIN32_MMAP = YesPlease
 	COMPAT_CFLAGS += -D__USE_MINGW_ACCESS -DNOGDI -Icompat -Icompat/regex -Icompat/fnmatch
 	COMPAT_CFLAGS += -DSNPRINTF_SIZE_CORR=1
 	COMPAT_CFLAGS += -DSTRIP_EXTENSION=\".exe\"
@@ -985,6 +985,11 @@ endif
 ifdef NO_MMAP
 	COMPAT_CFLAGS += -DNO_MMAP
 	COMPAT_OBJS += compat/mmap.o
+else
+	ifdef USE_WIN32_MMAP
+		COMPAT_CFLAGS += -DUSE_WIN32_MMAP
+		COMPAT_OBJS += compat/win32mmap.o
+	endif
 endif
 ifdef NO_PREAD
 	COMPAT_CFLAGS += -DNO_PREAD
diff --git a/compat/mingw.h b/compat/mingw.h
index 7e52f3607f..762eb143a7 100644
--- a/compat/mingw.h
+++ b/compat/mingw.h
@@ -159,6 +159,11 @@ int mingw_connect(int sockfd, struct sockaddr *sa, size_t sz);
 int mingw_rename(const char*, const char*);
 #define rename mingw_rename
 
+#ifdef USE_WIN32_MMAP
+int mingw_getpagesize(void);
+#define getpagesize mingw_getpagesize
+#endif
+
 /* Use mingw_lstat() instead of lstat()/stat() and
  * mingw_fstat() instead of fstat() on Windows.
  */
diff --git a/compat/win32mmap.c b/compat/win32mmap.c
new file mode 100644
index 0000000000..779d796cd5
--- /dev/null
+++ b/compat/win32mmap.c
@@ -0,0 +1,53 @@
+#include "../git-compat-util.h"
+
+/*
+ * Note that this doesn't return the actual pagesize, but
+ * the allocation granularity. If future Windows specific git code
+ * needs the real getpagesize function, we need to find another solution.
+ */
+int mingw_getpagesize(void)
+{
+	SYSTEM_INFO si;
+	GetSystemInfo(&si);
+	return si.dwAllocationGranularity;
+}
+
+void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+{
+	HANDLE hmap;
+	void *temp;
+	size_t len;
+	struct stat st;
+	uint64_t o = offset;
+	uint32_t l = o & 0xFFFFFFFF;
+	uint32_t h = (o >> 32) & 0xFFFFFFFF;
+
+	if (!fstat(fd, &st))
+		len = xsize_t(st.st_size);
+	else
+		die("mmap: could not determine filesize");
+
+	if ((length + offset) > len)
+		length = len - offset;
+
+	if (!(flags & MAP_PRIVATE))
+		die("Invalid usage of mmap when built with USE_WIN32_MMAP");
+
+	hmap = CreateFileMapping((HANDLE)_get_osfhandle(fd), 0, PAGE_WRITECOPY,
+		0, 0, 0);
+
+	if (!hmap)
+		return MAP_FAILED;
+
+	temp = MapViewOfFileEx(hmap, FILE_MAP_COPY, h, l, length, start);
+
+	if (!CloseHandle(hmap))
+		warning("unable to close file mapping handle\n");
+
+	return temp ? temp : MAP_FAILED;
+}
+
+int git_munmap(void *start, size_t length)
+{
+	return !UnmapViewOfFile(start);
+}
diff --git a/git-compat-util.h b/git-compat-util.h
index 19062534a1..f09f244061 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -166,7 +166,7 @@ static inline const char *skip_prefix(const char *str, const char *prefix)
 	return strncmp(str, prefix, len) ? NULL : str + len;
 }
 
-#ifdef NO_MMAP
+#if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
 
 #ifndef PROT_READ
 #define PROT_READ 1
@@ -180,13 +180,19 @@ static inline const char *skip_prefix(const char *str, const char *prefix)
 extern void *git_mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset);
 extern int git_munmap(void *start, size_t length);
 
+#else /* NO_MMAP || USE_WIN32_MMAP */
+
+#include <sys/mman.h>
+
+#endif /* NO_MMAP || USE_WIN32_MMAP */
+
+#ifdef NO_MMAP
+
 /* This value must be multiple of (pagesize * 2) */
 #define DEFAULT_PACKED_GIT_WINDOW_SIZE (1 * 1024 * 1024)
 
 #else /* NO_MMAP */
 
-#include <sys/mman.h>
-
 /* This value must be multiple of (pagesize * 2) */
 #define DEFAULT_PACKED_GIT_WINDOW_SIZE \
 	(sizeof(void*) >= 8 \