diff -Naur ktechlab-0.3.7.orig/src/electronics/port.cpp ktechlab-0.3.7/src/electronics/port.cpp
--- ktechlab-0.3.7.orig/src/electronics/port.cpp	2009-01-28 17:13:29.000000000 +0100
+++ ktechlab-0.3.7/src/electronics/port.cpp	2017-02-23 16:48:27.331987630 +0100
@@ -274,13 +274,13 @@
 	#define PPRELEASE 	0xCAFE
 #endif
 
-const int IOCTL_REG_READ[3] = {
+const unsigned long IOCTL_REG_READ[3] = {
 	PPRDATA,
 	PPRSTATUS,
 	PPRCONTROL,
 };
 
-const int IOCTL_REG_WRITE[3] = {
+const unsigned long IOCTL_REG_WRITE[3] = {
 	PPWDATA,
 	0,
 	PPWCONTROL,