--- src/tools/ATVersion.cpp.old	2014-05-07 20:57:07.086894124 +0200
+++ src/tools/ATVersion.cpp	2014-05-07 20:57:32.906640035 +0200
@@ -40,6 +40,7 @@
 #include <cerrno>
 #include <fstream>
 #include <dirent.h>
+#include <unistd.h>
 
 #define AT_VERSION_ARGUMENT "--version"
 #define AT_VERSION_MAXSIZE 40