diff --git a/assets/css/lesson.css b/assets/css/lesson.css
index 16a199fec6985e7991605c338758f30fcb1dc9e4..6277334803584e0dee89a3a20471795d20933f54 100644
--- a/assets/css/lesson.css
+++ b/assets/css/lesson.css
@@ -318,3 +318,25 @@ ol {
 span.fold-unfold {
   margin-left: 1em;
   opacity: 0.5; }
+
+/* version added automatically */
+div.navbar-header:hover::before {
+    content: "[DOI: 10.5281/zenodo.838778] ";
+}
+div.navbar-header::before {
+    content: "Version 2017.08";
+    font-size: 10px;
+    font-family: monospace;
+    font-weight: bold;
+    line-height: 1;
+    /* */
+    position: fixed;
+    right: 0;
+    top: 0;
+    z-index: 10;
+    /* */
+    color: white;
+    background: rgb(43, 57, 144);
+    padding: 3px;
+    border: 1px solid white;
+}
\ No newline at end of file