1 files changed, 10 insertions, 0 deletions
diff --git a/library/alloc/src/boxed/thin.rs b/library/alloc/src/boxed/thin.rs
index 649ccfcaa..0a20c74b0 100644
--- a/library/alloc/src/boxed/thin.rs
+++ b/library/alloc/src/boxed/thin.rs
@@ -2,6 +2,8 @@
 // https://github.com/matthieu-m/rfc2580/blob/b58d1d3cba0d4b5e859d3617ea2d0943aaa31329/examples/thin.rs
 // by matthieu-m
 use crate::alloc::{self, Layout, LayoutError};
+#[cfg(not(bootstrap))]
+use core::error::Error;
 use core::fmt::{self, Debug, Display, Formatter};
 use core::marker::PhantomData;
 #[cfg(not(no_global_oom_handling))]
@@ -271,3 +273,11 @@ impl<H> WithHeader<H> {
         Layout::new::<H>().extend(value_layout)
     }
 }
+
+#[cfg(not(bootstrap))]
+#[unstable(feature = "thin_box", issue = "92791")]
+impl<T: ?Sized + Error> Error for ThinBox<T> {
+    fn source(&self) -> Option<&(dyn Error + 'static)> {
+        self.deref().source()
+    }
+}