diff --git a/package.json b/package.json
index e02992b..f352963 100644
--- a/package.json
+++ b/package.json
@@ -17,23 +17,19 @@
     "bugs": {
         "url" : "http://github.com/ozra/mmap-io/issues"
     },
-
     "scripts": {
-        "prepublish":   "make ls",
+        "prepare":      "lsc -b -c -o ./ src/mmap-io.ls src/test.ls",
         "install":      "node-gyp configure && node-gyp rebuild",
         "test":         "node ./test.js"
     },
-
     "devDependencies": {
         "errno": "*",
         "LiveScript": "1.*.*"
     },
-
     "dependencies": {
         "bindings": "1.*.*",
         "nan":      "2.*.*"
     },
-
     "main":     "mmap-io",
     "engines": {
         "node": ">=0.10.0"
diff --git a/src/mman.h b/src/mman.h
index 7b8e979..78540dc 100644
--- a/src/mman.h
+++ b/src/mman.h
@@ -50,11 +50,11 @@ inline void* mmap(void* addr, size_t length, int prot, int flags, int fd, off_t
 
     off_t end = length + offset;
     const DWORD dwEndLow = (sizeof(off_t) > sizeof(DWORD)) ? DWORD(end & 0xFFFFFFFFL) : DWORD(end);
-    const DWORD dwEndHigh = (sizeof(off_t) > sizeof(DWORD)) ? DWORD(end & 0xFFFFFFFFL) : DWORD(0);
+    const DWORD dwEndHigh = (sizeof(off_t) > sizeof(DWORD)) ? DWORD((end >> 32) & 0xFFFFFFFFL) : DWORD(0);
     const DWORD dwOffsetLow = (sizeof(off_t) > sizeof(DWORD)) ? DWORD(offset & 0xFFFFFFFFL) : DWORD(offset);
-    const DWORD dwOffsetHigh = (sizeof(off_t) > sizeof(DWORD)) ? DWORD(offset & 0xFFFFFFFFL) : DWORD(0);
+    const DWORD dwOffsetHigh = (sizeof(off_t) > sizeof(DWORD)) ? DWORD((offset >> 32) & 0xFFFFFFFFL) : DWORD(0);
 
-    HANDLE h = (fd == -1) ? HANDLE(_get_osfhandle(fd)) : INVALID_HANDLE_VALUE;
+    HANDLE h = (fd != -1) ? HANDLE(uv_get_osfhandle(fd)) : INVALID_HANDLE_VALUE;
     HANDLE fm = CreateFileMapping(h, nullptr, protect, dwEndHigh, dwEndLow, nullptr);
     if (fm == nullptr)
         return MAP_FAILED;
@@ -94,3 +94,8 @@ inline int msync(void* addr, size_t length, int flags) {
 inline int madvise(void* addr, size_t length, int advice) {
     return 0;   // Unsupported on Windows
 }
+
+inline int mincore(void *addr, size_t length, unsigned char *vec) {
+    errno = ENOSYS;
+    return -1;
+}
diff --git a/src/mmap-io.cc b/src/mmap-io.cc
index df8252d..86aad2c 100644
--- a/src/mmap-io.cc
+++ b/src/mmap-io.cc
@@ -183,10 +183,13 @@ JS_FN(mmap_incore) {
             }
 
             int ret = mincore(data, size, resultData);
-
             if (ret) {
                 free(resultData);
-                return Nan::ThrowError((std::string("mincore() failed, ") + std::to_string(errno)).c_str());
+                if (errno == ENOSYS) {
+                  return Nan::ThrowError("mincore() not implemented");
+                } else {
+                  return Nan::ThrowError((std::string("mincore() failed, ") + std::to_string(errno)).c_str());
+                }
             }
 
             // Now we want to check all of the pages
diff --git a/src/test.ls b/src/test.ls
index dabcbdd..ca6a545 100644
--- a/src/test.ls
+++ b/src/test.ls
@@ -3,6 +3,7 @@
 # Some lines snatched from Ben Noordhuis test-script of "node-mmap"
 
 fs =        require "fs"
+os =        require "os"
 #mmap =      require "./build/Release/mmap-io.node"
 mmap =      require "./mmap-io"
 assert =    require "assert"
@@ -46,13 +47,15 @@ try
     for ix from (size - 1) to 0 by -1
         out += String.from-char-code(buffer[ix])
 
+    # not implemented on Win32
     incore_stats = mmap.incore(buffer)
     assert.equal(incore_stats[0], 0)
     assert.equal(incore_stats[1], 2)
 
     #say out, "\n\n"
 catch e
-    assert false, "Shit happened while reading from buffer"
+    if e.message != 'mincore() not implemented'
+        assert false, "Shit happened while reading from buffer"
 
 try
     say "read out of bounds test"
@@ -82,10 +85,14 @@ assert.equal(buffer.length, size)
 
 # Snatched from Ben Noordhuis test-script:
 # page size is almost certainly >= 4K and this script isn't that large...
-fd = fs.open-sync(process.argv[1], 'r')
-buffer = mmap.map(size, PROT_READ, MAP_SHARED, fd, PAGESIZE)
-say "buflen test 3 = ", buffer.length
-assert.equal(buffer.length, size);    # ...but this is according to spec
+if os.type() != 'Windows_NT'
+    # XXX: this will always fail on Windows, as it requires that offset be a
+    # multiple of the dwAllocationGranularity, which is NOT the same as the
+    # pagesize.  In addition, the offset+length can't exceed the file size.
+    fd = fs.open-sync(process.argv[1], 'r')
+    buffer = mmap.map(size, PROT_READ, MAP_SHARED, fd, PAGESIZE)
+    say "buflen test 3 = ", buffer.length
+    assert.equal(buffer.length, size);    # ...but this is according to spec
 
 # non int param should throw exception
 fd = fs.open-sync(process.argv[1], 'r')