diff --git a/.travis.yml b/.travis.yml
index 4cecab1..23bda33 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -16,6 +16,6 @@ before_script:
 - rustup component add rustfmt
 
 script:
-- cargo clippy -- -D warnings
-- cargo test
+- cargo clippy --workspace -- -D warnings
+- cargo test --workspace
 - cargo fmt --all -- --check
diff --git a/simple-invaders/src/lib.rs b/simple-invaders/src/lib.rs
index 513ed97..599d9a7 100644
--- a/simple-invaders/src/lib.rs
+++ b/simple-invaders/src/lib.rs
@@ -228,6 +228,12 @@ impl World {
     }
 }
 
+impl Default for World {
+    fn default() -> Self {
+        World::new()
+    }
+}
+
 impl Point {
     const fn new(x: usize, y: usize) -> Point {
         Point { x, y }