diff --git a/collects/scribble/run.rkt b/collects/scribble/run.rkt
index 7d116842f0..526ddb3664 100644
--- a/collects/scribble/run.rkt
+++ b/collects/scribble/run.rkt
@@ -105,7 +105,11 @@
     (current-quiet #t)]
    #:args (file . another-file)
    (let ([files (cons file another-file)])
-     (build-docs (map (lambda (file) (dynamic-require `(file ,file) 'doc))
+     (build-docs (map (lambda (file) 
+                        ;; Try `doc' submodule, first:
+                        (if (module-declared? `(submod (file ,file) doc) #t)
+                            (dynamic-require `(submod (file ,file) doc) 'doc)
+                            (dynamic-require `(file ,file) 'doc)))
                       files)
                  files))))
 
diff --git a/collects/scribblings/scribble/running.scrbl b/collects/scribblings/scribble/running.scrbl
index 74e94a1fc0..c762370eb6 100644
--- a/collects/scribblings/scribble/running.scrbl
+++ b/collects/scribblings/scribble/running.scrbl
@@ -51,9 +51,16 @@ flag to specify a destination directory (for any number of source
 files). Use @DFlag{dest-base} to add a prefix to the name of each
 support file that is generated or copied to the destination.
 
-After all flags, provide one or more document sources. When multiple
-documents are rendered at the same time, cross-reference information
-in one document is visible to the other documents. See
+After all flags, provide one or more document sources, where each
+source declares a module. The module should either have a @racket[doc]
+@tech[#:doc '(lib "scribblings/reference/reference.scrbl")]{submodule}
+that exports @racket[doc] as a @racket[part], or it should directly
+export @racket[doc] as a @racket[part]. (The submodule is tried first,
+and the main module is not directly loaded or evaluated if the
+submodule can be loaded on its own.)
+
+When multiple documents are rendered at the same time, cross-reference
+information in one document is visible to the other documents. See
 @secref["xref-flags"] for information on references that cross
 documents that are built separately.
 
diff --git a/collects/setup/scribble.rkt b/collects/setup/scribble.rkt
index 06c9e5fd12..930d330bab 100644
--- a/collects/setup/scribble.rkt
+++ b/collects/setup/scribble.rkt
@@ -1072,7 +1072,15 @@
       ;;  hard-wiring the "manual.rkt" library:
       (namespace-attach-module ns 'scribble/manual p)
       (parameterize ([current-namespace p])
-        (call-in-nested-thread (lambda () (dynamic-require mod-path 'doc)))))))
+        (call-in-nested-thread (lambda ()
+                                 (define sub
+                                   (if (and (pair? mod-path)
+                                            (eq? (car mod-path) 'submod))
+                                       (append mod-path '(doc))
+                                       `(submod ,mod-path doc)))
+                                 (if (module-declared? sub #t)
+                                     (dynamic-require sub 'doc)
+                                     (dynamic-require mod-path 'doc))))))))
 
 (define (write- latex-dest vers doc name datas prep!)
   (let* ([filename (sxref-path latex-dest doc name)])