diff --git a/lists/src/first.rs b/lists/src/first.rs
index f34b332..3a0aa3e 100644
--- a/lists/src/first.rs
+++ b/lists/src/first.rs
@@ -21,7 +21,7 @@ impl List {
 
     pub fn push(&mut self, elem: i32) {
         let new_node = Box::new(Node {
-            elem: elem,
+            elem,
             next: mem::replace(&mut self.head, Link::Empty),
         });
 
@@ -39,6 +39,12 @@ impl List {
     }
 }
 
+impl Default for List {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
 impl Drop for List {
     fn drop(&mut self) {
         let mut cur_link = mem::replace(&mut self.head, Link::Empty);