1 files changed, 4 insertions, 2 deletions
diff --git a/library/alloc/src/rc.rs b/library/alloc/src/rc.rs
index aed3357afbf..023238a00db 100644
--- a/library/alloc/src/rc.rs
+++ b/library/alloc/src/rc.rs
@@ -277,7 +277,9 @@ use crate::vec::Vec;
 // This is repr(C) to future-proof against possible field-reordering, which
 // would interfere with otherwise safe [into|from]_raw() of transmutable
 // inner types.
-#[repr(C)]
+// repr(align(2)) (forcing alignment to at least 2) is required because usize
+// has 1-byte alignment on AVR.
+#[repr(C, align(2))]
 struct RcInner<T: ?Sized> {
     strong: Cell<usize>,
     weak: Cell<usize>,
@@ -2377,7 +2379,7 @@ impl<T> Default for Rc<[T]> {
 }
 
 #[cfg(not(no_global_oom_handling))]
-#[stable(feature = "pin_default_impls", since = "CURRENT_RUSTC_VERSION")]
+#[stable(feature = "pin_default_impls", since = "1.91.0")]
 impl<T> Default for Pin<Rc<T>>
 where
     T: ?Sized,