diff --git a/akka-docs-dev/_sphinx/themes/akka/layout.html b/akka-docs-dev/_sphinx/themes/akka/layout.html
index 1cdc293ad3..010150742e 100644
--- a/akka-docs-dev/_sphinx/themes/akka/layout.html
+++ b/akka-docs-dev/_sphinx/themes/akka/layout.html
@@ -11,6 +11,7 @@
 {% set script_files = script_files + ['_static/effects.highlight.js'] %}
 {% set script_files = script_files + ['_static/scrollTo.js'] %}
 {% set script_files = script_files + ['_static/contentsFix.js'] %}
+{% set script_files = script_files + ['_static/warnOldDocs.js'] %}
 {% set script_files = script_files + ['_static/ga.js'] %}
 {% set css_files = css_files + ['_static/prettify.css'] %}
 {% set css_files = css_files + ['_static/base.css'] %}
diff --git a/akka-docs-dev/_sphinx/themes/akka/static/docs.css b/akka-docs-dev/_sphinx/themes/akka/static/docs.css
index d9afa16d5d..6c6de15ca1 100644
--- a/akka-docs-dev/_sphinx/themes/akka/static/docs.css
+++ b/akka-docs-dev/_sphinx/themes/akka/static/docs.css
@@ -177,3 +177,34 @@ strong {color: #0B5567; }
 .section-marker { position: absolute; width: 1em; margin-left: -1em; display: block; text-decoration: none; visibility: hidden; text-align: center; font-weight: normal; }
 .section-marker:hover { text-decoration: none; }
 .section h2:hover > a,.section h3:hover > a,.section h4:hover > a,.section h5:hover > a { visibility: visible; }
+
+
+/* floaty warning about old version of docs */
+#floaty-warning {
+  display: none;
+  position: fixed;
+  bottom: 0;
+  left: 0;
+  margin-bottom: 0;
+  z-index: 99999;
+  width: 100%;
+  background-color: rgb(84, 180, 204);
+  text-align: center;
+  padding: 10px;
+  color: white;
+}
+
+#floaty-warning a {
+  color: white;
+  font-weight: bold;
+  text-decoration: underline;
+}
+
+#close-floaty-window {
+  position: absolute;
+  top: 1em;
+  right: 2em;
+  color: white;
+  font-weight: normal;
+  text-decoration: none;
+}