diff --git a/sass/css/base.scss b/sass/css/base.scss
index afabae3..e08419e 100644
--- a/sass/css/base.scss
+++ b/sass/css/base.scss
@@ -1,3 +1,18 @@
+#dev-warning {
+	position: fixed;
+	top: 48px;
+	left: 0;
+	width: 256px;
+	background-color: #fa0;
+	border-bottom: 4px dashed #000;
+	border-right: 4px dashed #000;
+	border-top: 4px dashed #000;
+	border-bottom-right-radius: 16px;
+	border-top-right-radius: 16px;
+	padding: 4px;
+	font-size: 20px;
+}
+
 @font-face {
 	font-family: Amatic;
 	src: url("/fonts/AmaticSC-Bold.woff2");
diff --git a/templates/base.html b/templates/base.html
index 02cf58c..1d8e4e3 100644
--- a/templates/base.html
+++ b/templates/base.html
@@ -7,9 +7,16 @@
 		<link rel="stylesheet" href="/css/base.css"/>
 		<link rel="shortcut icon" type="image/x-icon" href="/favicon.ico"/>
 		<meta name="viewport" content="width=device-width"/>
+		<meta name="robots" content="noindex,nofollow"/><!-- TODO remove this for production -->
 		{% block head %}{% endblock head %}
 	</head>
 	<body>
+		<div id="dev-warning">
+			<p>
+				Version de développement. Pour le site officiel actuel, allez sur <a href="https://librezo.com"><b>Librezo.com</b></a>.
+			</p>
+			<a href="#" onclick="document.getElementById('dev-warning').remove()">fermer</a>
+		</div>
 		<header>
 			<a href="/"><img id="header-logo" src="/img/librezo-little-black.png" alt="Logo Librezo" aria-hidden/><h1 class="sr-only">Librezo</h1></a>
 			<nav id="header-menu">
