diff --git a/app/background/index.html b/app/background/index.html
index 2e72d4ce..b1681abc 100644
--- a/app/background/index.html
+++ b/app/background/index.html
@@ -1,6 +1,7 @@
 <!doctype html>
 <html>
   <head>
+    <meta charset="utf-8">
     <script>
       (function() {
         const script = document.createElement('script');
