diff --git a/memfs.py b/memfs.py
index 88c41dbe6..01f71c754 100755
--- a/memfs.py
+++ b/memfs.py
@@ -8,7 +8,7 @@ import binascii
 assert len(sys.argv) > 2
 
 # For now exclude GRIB3 as it is still experimental
-EXCLUDED = 'grib3'
+EXCLUDED = ['grib3']
 
 dirs = [os.path.realpath(x) for x in sys.argv[1:-1]]
 print(dirs)
@@ -35,17 +35,19 @@ for directory in dirs:
     NAMES.append(dname)
 
     for dirpath, dirnames, files in os.walk(directory, followlinks=True):
-        if EXCLUDED in dirnames:
-            print('Note: %s/%s will not be included.' % (dirpath,EXCLUDED))
+        for ex in EXCLUDED:
+            if ex in dirnames:
+                print('Note: %s/%s will not be included.' % (dirpath,ex))
 
         # Prune the walk by modifying the dirnames in-place
-        dirnames[:] = [dirname for dirname in dirnames if dirname != EXCLUDED]
+        dirnames[:] = [dirname for dirname in dirnames if dirname not in EXCLUDED]
         for name in files:
             full = '%s/%s' % (dirpath, name)
             _, ext = os.path.splitext(full)
             if ext not in ['.def', '.table', '.tmpl']:
                 continue
 
+            full = full.replace("\\","/")
             fname = full[full.find("/%s/" % (dname,)):]
             #print("MEMFS add", fname)
             name = re.sub(r'\W', '_', fname)
@@ -171,6 +173,49 @@ static FILE* fmemopen(const char* buffer, size_t size, const char* mode){
     return funopen(f, &read_mem, &write_mem, &seek_mem, &close_mem);
 }
 
+#elif defined(ECCODES_ON_WINDOWS)
+
+#include <io.h>
+#include <fcntl.h>
+#include <windows.h>
+
+static FILE *fmemopen(void* buffer, size_t size, const char* mode) {
+    char path[MAX_PATH - 13];
+    if (!GetTempPath(sizeof(path), path))
+        return NULL;
+
+    char filename[MAX_PATH + 1];
+    if (!GetTempFileName(path, "eccodes", 0, filename))
+        return NULL;
+
+    HANDLE h = CreateFile(filename,
+                          GENERIC_READ | GENERIC_WRITE,
+                          0,
+                          NULL,
+                          OPEN_ALWAYS,
+                          FILE_ATTRIBUTE_TEMPORARY | FILE_FLAG_DELETE_ON_CLOSE,
+                          NULL);
+
+    if (h == INVALID_HANDLE_VALUE)
+        return NULL;
+
+    int fd = _open_osfhandle((intptr_t)h, _O_RDWR);
+    if (fd < 0) {
+        CloseHandle(h);
+        return NULL;
+    }
+
+    FILE* f = _fdopen(fd, "w+");
+    if (!f) {
+        _close(fd);
+        return NULL;
+    }
+
+    fwrite(buffer, size, 1, f);
+    rewind(f);
+    return f;
+}
+
 #endif
 
 static size_t entries_count = sizeof(entries)/sizeof(entries[0]);