diff --git a/docs/ref/contrib/admin/index.txt b/docs/ref/contrib/admin/index.txt
index 3f32d3bce4..cbf7d4215b 100644
--- a/docs/ref/contrib/admin/index.txt
+++ b/docs/ref/contrib/admin/index.txt
@@ -271,7 +271,7 @@ subclass::
         Example::
 
             {
-            'classes': ['wide', 'extrapretty'],
+            'classes': ('wide', 'extrapretty'),
             }
 
         Two useful classes defined by the default admin site stylesheet are