diff --git a/collects/scribble/base-render.rkt b/collects/scribble/base-render.rkt
index 7de7a0b3..2a5cace6 100644
--- a/collects/scribble/base-render.rkt
+++ b/collects/scribble/base-render.rkt
@@ -207,7 +207,7 @@
     ;; marshal info
 
     (define/public (get-serialize-version)
-      3)
+      4)
 
     (define/public (serialize-info ri)
       (parameterize ([current-serialize-resolve-info ri])