diff --git a/src/base/default_allocator.rs b/src/base/default_allocator.rs
index 2435c4eb..cbfb5f61 100644
--- a/src/base/default_allocator.rs
+++ b/src/base/default_allocator.rs
@@ -46,6 +46,7 @@ where
 
     #[inline]
     unsafe fn allocate_uninitialized(_: R, _: C) -> Self::Buffer {
+        // TODO: Undefined behavior, see #556
         mem::MaybeUninit::<Self::Buffer>::uninit().assume_init()
     }