diff --git a/src/H5PartTypes.h b/src/H5PartTypes.h
index 6f12601..89a123e 100644
--- a/src/H5PartTypes.h
+++ b/src/H5PartTypes.h
@@ -5,6 +5,9 @@
 #ifndef _H5PARTTYPES_H_
 #define _H5PARTTYPES_H_
 
+#ifdef   WIN32
+typdef __int64			int64_t;
+#endif /* WIN32 */
 
 typedef int64_t			h5part_int64_t;
 typedef double			h5part_float64_t;