diff --git a/src/21599.rs b/src/21599.rs
new file mode 100644
index 00000000..1ab74d87
--- /dev/null
+++ b/src/21599.rs
@@ -0,0 +1,19 @@
+#![no_std]
+#![feature(box_syntax,unique)]
+#![feature(no_std,lang_items)]
+
+use core::ptr::Unique;
+
+#[lang="owned_box"]
+pub struct Box<T>(Unique<T>);
+
+#[lang="start"]
+fn main() {
+    let mut test:[isize;1] = [0;1];
+    let a = box 5;
+    test[*a] = 0;
+}
+
+#[lang = "exchange_malloc"] extern fn exchange_malloc() {}
+#[lang = "eh_personality"] extern fn eh_personality() {}
+#[lang = "panic_fmt"] fn panic_fmt() -> ! { loop{} }