diff --git a/library/alloc/tests/gc.rs b/library/alloc/tests/gc.rs
new file mode 100644
index 0000000000000..be25f93d38a4a
--- /dev/null
+++ b/library/alloc/tests/gc.rs
@@ -0,0 +1,12 @@
+use std::gc::GcAllocator;
+
+#[repr(align(1024))]
+struct S(u8);
+
+#[test]
+fn large_alignment() {
+    let x = Box::new_in(S(123), GcAllocator);
+    let ptr = Box::into_raw(x);
+    assert!(!ptr.is_null());
+    assert!(ptr.is_aligned());
+}
diff --git a/library/alloc/tests/lib.rs b/library/alloc/tests/lib.rs
index 2529c8384764a..1bc2b7dc08e8f 100644
--- a/library/alloc/tests/lib.rs
+++ b/library/alloc/tests/lib.rs
@@ -56,6 +56,7 @@ mod c_str;
 mod const_fns;
 mod cow_str;
 mod fmt;
+mod gc;
 mod heap;
 mod linked_list;
 mod rc;