diff --git a/kernel/syscall/skeleton.cc b/kernel/syscall/skeleton.cc
index b27aeae..04694e1 100644
--- a/kernel/syscall/skeleton.cc
+++ b/kernel/syscall/skeleton.cc
@@ -71,15 +71,13 @@ bool sem_destroy(Vault &vault, size_t id) {
 }
 
 bool sem_signal(Vault &vault, size_t id) {
-	(void)vault;
-	(void)id;
+  vault.sems[id].v(vault);
 
   return true;
 }
 
 bool sem_wait(Vault &vault, size_t id) {
-	(void)vault;
-	(void)id;
+  vault.sems[id].p(vault);
   return true;
 }