Index: /trunk/Config.kmk
===================================================================
--- /trunk/Config.kmk	(revision 15979)
+++ /trunk/Config.kmk	(revision 15980)
@@ -1865,4 +1865,5 @@
    export VBOX_LINUX_INCS           := $(VBOX_LINUX_SRC)/include
    # XXX hack alert! support splitted Linux kernels (make O=<build directory>)
+   # XXX put this crap elsewhere
    kernelsrc := $(shell $(SED_EXT) -ne 's+^KERNELSRC.*= *\(.*\)+\1+p' $(VBOX_LINUX_SRC)/Makefile)
    ifneq ($(kernelsrc),)
@@ -1871,4 +1872,10 @@
     # Linux >= 2.6.25
     kernelpath := $(shell $(SED_EXT) -ne 's+^MAKEARGS *:= *-C *\(.*\)+\1+p' $(VBOX_LINUX_SRC)/Makefile)
+    ifneq ($(kernelpath),)
+     ifneq ($(patsubst /%,,$(kernelpath)),)
+      # relative path
+      kernelpath := $(realpath $(VBOX_LINUX_SRC)/$(kernelpath))
+     endif
+    endif
    endif
    ifneq ($(kernelpath),)