--- a/unmodified_drivers/linux-2.6/blkfront/Kbuild
+++ b/unmodified_drivers/linux-2.6/blkfront/Kbuild
@@ -3,3 +3,4 @@ include $(M)/overrides.mk
 obj-m += xen-vbd.o
 
 xen-vbd-objs := blkfront.o vbd.o
+xen-vbd-objs += $(patsubst %.c,%.o,$(notdir $(wildcard $(src)/vcd.c)))