Explicitly specify alignment of 64-bit types.
diff --git a/include/basetsd.h b/include/basetsd.h
index 615b371..274f41b 100644
--- a/include/basetsd.h
+++ b/include/basetsd.h
@@ -59,20 +59,31 @@
# endif
#endif /* !defined(_MSC_VER) */
+/* FIXME: DECLSPEC_ALIGN should be declared only in winnt.h, but we need it here too */
+#ifndef DECLSPEC_ALIGN
+# if defined(_MSC_VER) && (_MSC_VER >= 1300) && !defined(MIDL_PASS)
+# define DECLSPEC_ALIGN(x) __declspec(align(x))
+# elif defined(__GNUC__)
+# define DECLSPEC_ALIGN(x) __attribute__((aligned(x)))
+# else
+# define DECLSPEC_ALIGN(x)
+# endif
+#endif
+
typedef signed char INT8, *PINT8;
typedef signed short INT16, *PINT16;
typedef signed int INT32, *PINT32;
-typedef signed __int64 INT64, *PINT64;
+typedef signed __int64 DECLSPEC_ALIGN(8) INT64, *PINT64;
typedef unsigned char UINT8, *PUINT8;
typedef unsigned short UINT16, *PUINT16;
typedef unsigned int UINT32, *PUINT32;
-typedef unsigned __int64 UINT64, *PUINT64;
+typedef unsigned __int64 DECLSPEC_ALIGN(8) UINT64, *PUINT64;
typedef signed int LONG32, *PLONG32;
typedef unsigned int ULONG32, *PULONG32;
typedef unsigned int DWORD32, *PDWORD32;
-typedef signed __int64 LONG64, *PLONG64;
-typedef unsigned __int64 ULONG64, *PULONG64;
-typedef unsigned __int64 DWORD64, *PDWORD64;
+typedef signed __int64 DECLSPEC_ALIGN(8) LONG64, *PLONG64;
+typedef unsigned __int64 DECLSPEC_ALIGN(8) ULONG64, *PULONG64;
+typedef unsigned __int64 DECLSPEC_ALIGN(8) DWORD64, *PDWORD64;
/* Win32 or Win64 dependent typedef/defines. */
