Index: dll/win32/wshtcpip/wshtcpip.c
===================================================================
--- dll/win32/wshtcpip/wshtcpip.c	(revision 72964)
+++ dll/win32/wshtcpip/wshtcpip.c	(working copy)
@@ -355,7 +355,7 @@
 
     DPRINT1("Ioctl: Unknown IOCTL code: %d\n", IoControlCode);
 
-    return NO_ERROR;
+    return WSAEINVAL;
 }