diff --git a/doc-tool/resources/_layouts/main.html b/doc-tool/resources/_layouts/main.html
index 364da6fb7ade..137d517f1bbf 100644
--- a/doc-tool/resources/_layouts/main.html
+++ b/doc-tool/resources/_layouts/main.html
@@ -61,5 +61,12 @@
                 }
             });
         </script>
+
+        <script>
+          ((window.gitter = {}).chat = {}).options = {
+            room: 'lampepfl/dotty'
+          };
+        </script>
+        <script src="https://sidecar.gitter.im/dist/sidecar.v1.js" async defer></script>
     </body>
 </html>
diff --git a/doc-tool/resources/css/dottydoc.css b/doc-tool/resources/css/dottydoc.css
index 46055f35bc34..350559355141 100644
--- a/doc-tool/resources/css/dottydoc.css
+++ b/doc-tool/resources/css/dottydoc.css
@@ -270,3 +270,7 @@ aside.success {
     border-left: 3px solid #36bf1d;
     background-color: #ebfddd;
 }
+
+.gitter-open-chat-button {
+  background-color: gray;
+}