diff --git a/lab3/starter/shm/shm_stack.c b/lab3/starter/shm/shm_stack.c
index ddaedc35..637695a8 100644
--- a/lab3/starter/shm/shm_stack.c
+++ b/lab3/starter/shm/shm_stack.c
@@ -73,7 +73,7 @@ int init_shm_stack(ISTACK *p, int stack_size)
 
     p->size = stack_size;
     p->pos  = -1;
-    p->items = (int *) (p + sizeof(ISTACK));
+    p->items = (int *) ((char *)p + sizeof(ISTACK));
     return 0;
 }