diff --git a/build.sh b/build.sh
index 4500238..68dabfc 100755
--- a/build.sh
+++ b/build.sh
@@ -3,4 +3,4 @@
 mkdir -p dist
 tsc -p .
 webpack ./js/app.js -o dist/ --mode production
-cp index.html *.wav ui.css preview.png dist
+cp index.html *.mp3 ui.css preview.png dist