diff --git a/sys/include/wait.h b/sys/include/wait.h
index 8c1c6bf..e1903bb 100644
--- a/sys/include/wait.h
+++ b/sys/include/wait.h
@@ -4,8 +4,12 @@
 
 #include <sys/cdefs.h>
 
-/* Extract the status code from the process */
+/* Extract the status code from the status */
 #define WEXITSTATUS(_x)	(_x & 0x000000ff)
+#define _WSTATUS(_x) ((_x & 0x0000ff00) >> 8)
+/* Exited gracefully */
+#define WIFEXITED(_x) (_WSTATUS(_x) == 0)
+/* Extract the pid from the status (Castor specific) */
 #define WGETPID(_x)	((pid_t)(_x >> 16))
 
 /* Flags to waitpid  */