--- a/src/th06/enemy.rs
+++ b/src/th06/enemy.rs
@@ -359,6 +359,11 @@ impl Enemy {
         }
     }
 
+    /// Stubbed for now.
+    pub(crate) fn play_sound(&self, sound_index: i32) {
+        println!("Playing sound {}!", sound_index);
+    }
+
     /// Run all interpolators and such, and update internal variables once per
     /// frame.
     pub fn update(&mut self) {