diff --git a/exercises/16_lifetimes/lifetimes3.rs b/exercises/16_lifetimes/lifetimes3.rs
index 9c59f9c0..aede10de 100644
--- a/exercises/16_lifetimes/lifetimes3.rs
+++ b/exercises/16_lifetimes/lifetimes3.rs
@@ -5,11 +5,9 @@
 // Execute `rustlings hint lifetimes3` or use the `hint` watch subcommand for a
 // hint.
 
-// I AM NOT DONE
-
-struct Book {
-    author: &str,
-    title: &str,
+struct Book<'a> {
+    author: &'a str,
+    title: &'a str,
 }
 
 fn main() {