diff --git a/demos/er.html b/demos/er.html
index 49f0a683f0..65e3049c8c 100644
--- a/demos/er.html
+++ b/demos/er.html
@@ -21,6 +21,8 @@
     <pre class="mermaid">
       ---
       title: This is a title
+      config:
+        theme: forest
       ---
       erDiagram
         %% title This is a title
diff --git a/demos/flowchart.html b/demos/flowchart.html
index 92c5bbd6e4..8389510b28 100644
--- a/demos/flowchart.html
+++ b/demos/flowchart.html
@@ -123,6 +123,13 @@ <h3>graph</h3>
 
     <h3>flowchart</h3>
     <pre class="mermaid">
+    ---
+    title: This is another complicated flow
+    config:
+      theme: base
+      flowchart:
+        curve: cardinal
+    ---
     flowchart LR
     sid-B3655226-6C29-4D00-B685-3D5C734DC7E1["