diff --git a/pyopencl/cffi_cl.py b/pyopencl/cffi_cl.py
index f4d55faa52e8dd2ccf7f3468aed6b9e5c1794a64..d45d867453c34977d8f6a49ce8fca513836059df 100644
--- a/pyopencl/cffi_cl.py
+++ b/pyopencl/cffi_cl.py
@@ -732,7 +732,7 @@ def _parse_context_properties(properties):
             props.append(value.int_ptr)
 
         elif prop == getattr(context_properties, "WGL_HDC_KHR", None):
-            props.append(value)
+            props.append(ctypes.c_ssize_t(value).value)
 
         elif prop in [getattr(context_properties, key, None) for key in (
                 'CONTEXT_PROPERTY_USE_CGL_SHAREGROUP_APPLE',