diff --git a/library/core/src/slice/iter.rs b/library/core/src/slice/iter.rs
index 6e881b1e8b74..c5dffcf7e8f7 100644
--- a/library/core/src/slice/iter.rs
+++ b/library/core/src/slice/iter.rs
@@ -2260,6 +2260,9 @@ impl<T, const N: usize> ExactSizeIterator for ArrayWindows<'_, T, N> {
     }
 }
 
+#[unstable(feature = "trusted_len", issue = "37572")]
+unsafe impl<T, const N: usize> TrustedLen for ArrayWindows<'_, T, N> {}
+
 #[stable(feature = "array_windows", since = "1.94.0")]
 impl<T, const N: usize> FusedIterator for ArrayWindows<'_, T, N> {}