diff --git a/PC/winreg.c b/PC/winreg.c
index d23810b..63c437e 100644
--- a/PC/winreg.c
+++ b/PC/winreg.c
@@ -871,8 +871,10 @@
         /* ALSO handle ALL unknown data types here.  Even if we can't
            support it natively, we should handle the bits. */
         default:
-            if (value == Py_None)
+            if (value == Py_None) {
                 *retDataSize = 0;
+                *retDataBuf = NULL;
+            }
             else {
                 Py_buffer view;