diff --git a/library/core/src/any.rs b/library/core/src/any.rs
index 339e874558c..5e1725cfc7a 100644
--- a/library/core/src/any.rs
+++ b/library/core/src/any.rs
@@ -141,7 +141,7 @@ impl<T: 'static + ?Sized> Any for T {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl fmt::Debug for dyn Any {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Any").finish()
+        f.debug_struct("Any").finish_non_exhaustive()
     }
 }
 
@@ -151,14 +151,14 @@ impl fmt::Debug for dyn Any {
 #[stable(feature = "rust1", since = "1.0.0")]
 impl fmt::Debug for dyn Any + Send {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Any").finish()
+        f.debug_struct("Any").finish_non_exhaustive()
     }
 }
 
 #[stable(feature = "any_send_sync_methods", since = "1.28.0")]
 impl fmt::Debug for dyn Any + Send + Sync {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("Any").finish()
+        f.debug_struct("Any").finish_non_exhaustive()
     }
 }
 
diff --git a/library/core/src/fmt/mod.rs b/library/core/src/fmt/mod.rs
index 0edb7da5717..87042d95fbe 100644
--- a/library/core/src/fmt/mod.rs
+++ b/library/core/src/fmt/mod.rs
@@ -2270,7 +2270,7 @@ impl<T: ?Sized + Debug> Debug for RefMut<'_, T> {
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<T: ?Sized> Debug for UnsafeCell<T> {
     fn fmt(&self, f: &mut Formatter<'_>) -> Result {
-        f.debug_struct("UnsafeCell").finish()
+        f.debug_struct("UnsafeCell").finish_non_exhaustive()
     }
 }