diff --git a/js/spaceinvaders-core.js b/js/spaceinvaders-core.js
index 5baca4c..d5bef94 100644
--- a/js/spaceinvaders-core.js
+++ b/js/spaceinvaders-core.js
@@ -10,7 +10,7 @@
 
 Game = {
 	running : false,
-	wave_index : 0,
+	wave_index : -1,
 	wave : undefined,
 	aliens : [],
 	ship : null,