diff --git a/OpenGL/raw/WGL/_types.py b/OpenGL/raw/WGL/_types.py
index 99f950d4..650dd05a 100644
--- a/OpenGL/raw/WGL/_types.py
+++ b/OpenGL/raw/WGL/_types.py
@@ -1,5 +1,5 @@
 from ctypes import *
-from ctypes import _SimpleCData
+from ctypes import _SimpleCData, _check_size
 from OpenGL import extensions
 from OpenGL.raw.GL._types import *
 from OpenGL._bytes import as_8_bit