diff --git a/lang.rkt b/lang.rkt
index bca207bc..8458b4f8 100644
--- a/lang.rkt
+++ b/lang.rkt
@@ -2,4 +2,7 @@
 ;; Forked from scribble-lib/scribble/lp/lang/lang2.rkt
 (require "private/common.rkt")
 
-(provide (rename-out [module-begin/doc #%module-begin]))
+(provide (rename-out [module-begin/doc #%module-begin])
+         ;; TODO: this is the #%top-interaction from racket/base, not from the
+         ;; user-specified language.
+         #%top-interaction)