diff -up VirtualBox-5.1.6/src/libs/xpcom18a4/python/Makefile.kmk.python VirtualBox-5.1.6/src/libs/xpcom18a4/python/Makefile.kmk
--- VirtualBox-5.1.6/src/libs/xpcom18a4/python/Makefile.kmk.python	2016-09-12 18:20:10.000000000 +0200
+++ VirtualBox-5.1.6/src/libs/xpcom18a4/python/Makefile.kmk	2016-09-27 14:41:31.329030705 +0200
@@ -19,7 +19,7 @@ SUB_DEPTH = ../../../..
 include $(KBUILD_PATH)/subheader.kmk
 
 ifdef VBOX_WITH_MULTIVERSION_PYTHON
- VBOX_MULTIPYTHON = 1
+ VBOX_MULTIPYTHON = $(VBOX_WITH_MULTIVERSION_PYTHON)
 else
  VBOX_MULTIPYTHON = 0
 endif