diff --git a/doc/sandbox.mdwn b/doc/sandbox.mdwn
index 222f01b17..6d718ebfd 100644
--- a/doc/sandbox.mdwn
+++ b/doc/sandbox.mdwn
@@ -4,6 +4,12 @@ This is the SandBox, a page anyone can edit to try out ikiwiki.
 
 Here's a paragraph.
 
+The following code block is pre-formatted:
+
+    Testing what
+    pre-formatted code blocks
+    look like.
+
 Here's another one with *emphasised* text.
 
 # Header