diff --git a/Makefile b/Makefile
index d1207e1..bed2485 100644
--- a/Makefile
+++ b/Makefile
@@ -10,8 +10,11 @@ gpio-usbio-y := drivers/gpio/gpio-usbio.o
 obj-m += i2c-usbio.o
 i2c-usbio-y := drivers/i2c/busses/i2c-usbio.o
 
-KERNELRELEASE := $(shell uname -r)
-KDIR := /lib/modules/$(KERNELRELEASE)/build
+KERNELRELEASE ?= $(shell uname -r)
+KDIR ?= /lib/modules/$(KERNELRELEASE)/build
+ifdef KERNELDIR
+KDIR := $(KERNELDIR)
+endif
 PWD := $(shell pwd)
 
 ccflags-y += -I$(src)/include/
diff --git a/dkms.conf b/dkms.conf
index 8c38f21..7e4a910 100644
--- a/dkms.conf
+++ b/dkms.conf
@@ -1,5 +1,5 @@
 PACKAGE_NAME="usbio"
-PACKAGE_VERSION="0.2"
+PACKAGE_VERSION="0.3"
 
 MAKE="make -C . KERNELDIR=/lib/modules/${kernelver}/build"
 CLEAN="make -C . clean"