diff --git a/hermit/include/hermit/syscall.h b/hermit/include/hermit/syscall.h
index c5ebf0fdc..4a620cb62 100644
--- a/hermit/include/hermit/syscall.h
+++ b/hermit/include/hermit/syscall.h
@@ -84,6 +84,7 @@ extern "C" {
 #define __NR_getprio		39
 #define __NR_setprio		40
 #define __NR_clone		41
+#define __NR_sem_cancelablewait	42
 
 #ifdef __cplusplus
 }
diff --git a/hermit/kernel/syscall.c b/hermit/kernel/syscall.c
index 0c43a5acf..e6f641811 100644
--- a/hermit/kernel/syscall.c
+++ b/hermit/kernel/syscall.c
@@ -223,5 +223,6 @@ size_t syscall_table[] = {
 	(size_t) sys_sem_timedwait, 	/* __NR_sem_timedwait	*/
 	(size_t) sys_getprio,		/* __NR_getprio	*/
 	(size_t) default_handler,	/* __NR_setprio	*/
-	(size_t) sys_clone		/* __NR_clone	*/
+	(size_t) sys_clone,		/* __NR_clone	*/
+	(size_t) sys_sem_timedwait	/*  __NR_sem_cancelablewait	*/
 };