Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 6859)
+++ /trunk/Config.kmk	(revision 6860)
@@ -156,4 +156,13 @@
 if1of ($(BUILD_TARGET),l4 linux)
  VBOX_WITH_LINUX_ADDITIONS = 1
+endif
+# Build X11 additions. Can be disabled separately.
+ifndef VBOX_WITH_X11_ADDITIONS
+ ifdef VBOX_WITH_LINUX_ADDITIONS
+  VBOX_WITH_X11_ADDITIONS = 1
+ endif
+ if1of ($(BUILD_TARGET), solaris)
+  VBOX_WITH_X11_ADDITIONS = 1
+ endif
 endif
 # Enable the building of shared folders in the windows additions.
Index: /trunk/src/VBox/Additions/Makefile.kmk
===================================================================
--- /trunk/src/VBox/Additions/Makefile.kmk	(revision 6859)
+++ /trunk/src/VBox/Additions/Makefile.kmk	(revision 6860)
@@ -57,7 +57,7 @@
 endif
 ifdef VBOX_WITH_LINUX_ADDITIONS
- include $(PATH_SUB_CURRENT)/x11/Makefile.kmk
  include $(PATH_SUB_CURRENT)/linux/Makefile.kmk
-else if1of ($(BUILD_TARGET), solaris)
+endif
+ifdef VBOX_WITH_X11_ADDITIONS
  include $(PATH_SUB_CURRENT)/x11/Makefile.kmk
 endif