Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 59927)
+++ /trunk/Config.kmk	(revision 59928)
@@ -569,6 +569,10 @@
 VBOX_WITH_WEBSERVICES = 1
 VBOX_WITH_WEBSERVICES_SSL = 1
-# The Qt 4 GUI.
+# The Qt GUI (Qt4 by default).
 VBOX_WITH_QTGUI = 1
+ifeq ($(KBUILD_TARGET),win)
+# The Qt5 GUI.
+VBOX_WITH_QTGUI_V5 = 1
+endif
 # Indicates the Qt is Cocoa based on the Mac.
 ifeq ($(KBUILD_TARGET),darwin)