diff --git a/libraries/liblmdb/lmdb.h b/libraries/liblmdb/lmdb.h
index 9776366..2076eb3 100644
--- a/libraries/liblmdb/lmdb.h
+++ b/libraries/liblmdb/lmdb.h
@@ -144,12 +144,14 @@ typedef	int	mdb_mode_t;
 typedef	mode_t	mdb_mode_t;
 #endif
 
-#ifndef _WIN32
-	/** An abstraction for a file handle.
-	 *	On POSIX systems file handles are small integers. On Windows
-	 *	they're opaque pointers.
-	 */
-#define	HANDLE	int
+/** An abstraction for a file handle.
+ *	On POSIX systems file handles are small integers. On Windows
+ *	they're opaque pointers.
+ */
+#ifdef _WIN32
+typedef	void *mdb_filehandle_t;
+#else
+typedef int mdb_filehandle_t;
 #endif
 
 /** @defgroup mdb MDB API
@@ -550,7 +552,7 @@ int  mdb_env_copy(MDB_env *env, const char *path);
 	 * have already been opened for Write access.
 	 * @return A non-zero error value on failure and 0 on success.
 	 */
-int  mdb_env_copyfd(MDB_env *env, HANDLE fd);
+int  mdb_env_copyfd(MDB_env *env, mdb_filehandle_t fd);
 
 	/** @brief Return statistics about the MDB environment.
 	 *
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 4109e71..33b9d47 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -199,6 +199,12 @@ mdb_sem_wait(sem_t *sem)
 	 */
 #define	ErrCode()	errno
 
+	/** An abstraction for a file handle.
+	 *	On POSIX systems file handles are small integers. On Windows
+	 *	they're opaque pointers.
+	 */
+#define	HANDLE	int
+
 	/**	A value for an invalid file handle.
 	 *	Mainly used to initialize file variables and signify that they are
 	 *	unused.
@@ -3625,7 +3631,7 @@ mdb_env_close0(MDB_env *env, int excl)
 }
 
 int
-mdb_env_copyfd(MDB_env *env, int fd)
+mdb_env_copyfd(MDB_env *env, HANDLE fd)
 {
 	MDB_txn *txn = NULL;
 	int rc;