Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 54047)
+++ /trunk/Config.kmk	(revision 54048)
@@ -2872,8 +2872,8 @@
 
 #
-# Warn about windows hardening without code signing enabled.
+# Complain if windows hardening is enabled but not code signing.
 #
 else if "$(KBUILD_TARGET)" == "win" && defined(VBOX_WITH_HARDENING) && !defined(VBOX_ONLY_BUILD)
- $(warning You need to enable code signing for a hardened windows build to work.)
+ $(error You need to enable code signing for a hardened windows build to work.)
 endif