diff --git a/instance/index.html b/instance/index.html
index c37a7e92406e836eeae148c3f56f25c766b6e479..a61ba4c5468521a75476159e49a33fd71a6620e0 100644
--- a/instance/index.html
+++ b/instance/index.html
@@ -1,3 +1,12 @@
-<body>
-    toto
-</body>
+<!DOCTYPE html>
+<html>
+    <head>
+        <meta charset="UTF-8">
+        <title>Lektor App</title>
+        <!-- https://electronjs.org/docs/tutorial/security#csp-meta-tag -->
+        <meta http-equiv="Content-Security-Policy" content="script-src 'self' 'unsafe-inline';" />
+    </head>
+    <body>
+        toto
+    </body>
+</html>