diff --git a/collects/compiler/demodularizer/mpi.rkt b/collects/compiler/demodularizer/mpi.rkt
index bb430570dc..65c0b76ad7 100644
--- a/collects/compiler/demodularizer/mpi.rkt
+++ b/collects/compiler/demodularizer/mpi.rkt
@@ -18,16 +18,24 @@
    (lambda ()
      (define _pth
        (resolve-module-path-index mpi (current-module-path)))
-     (if (path? _pth)
-         (simplify-path _pth #t)
-         _pth))))
+     (cond
+      [(path? _pth) (simplify-path _pth #t)]
+      [(and (pair? _pth)
+            (path? (cadr _pth)))
+       (list* 'submod (simplify-path (cadr _pth) #t) (cddr _pth))]
+      [else _pth]))))
 (define (mpi->path* mpi)
   (hash-ref (MODULE-PATHS) mpi 
             (lambda ()
               (error 'mpi->path* "Cannot locate cache of path for ~S" mpi))))
 
+(define submod-path/c
+  (cons/c 'submod
+          (cons/c (or/c symbol? path?)
+                  (listof symbol?))))
+
 (provide/contract
  [MODULE-PATHS (parameter/c (or/c false/c hash?))]
- [current-module-path (parameter/c path-string?)]
- [mpi->path! (module-path-index? . -> . (or/c symbol? path?))]
- [mpi->path* (module-path-index? . -> . (or/c symbol? path?))])
+ [current-module-path (parameter/c (or/c path-string? submod-path/c))]
+ [mpi->path! (module-path-index? . -> . (or/c symbol? path? submod-path/c))]
+ [mpi->path* (module-path-index? . -> . (or/c symbol? path? pair? submod-path/c))])
diff --git a/collects/compiler/demodularizer/nodep.rkt b/collects/compiler/demodularizer/nodep.rkt
index 4e55b46545..f6c70e2bb1 100644
--- a/collects/compiler/demodularizer/nodep.rkt
+++ b/collects/compiler/demodularizer/nodep.rkt
@@ -28,13 +28,28 @@
       [(struct @phase (_ (struct module-code (modvar-rewrite lang-info ctop))))
        (values ctop lang-info (modvar-rewrite-modidx modvar-rewrite) get-modvar-rewrite)])))
 
-(define (path->comp-top pth)
-  (hash-ref! (ZOS) pth
+(define (path->comp-top pth submod)
+  (hash-ref! (ZOS) (cons pth submod)
              (λ ()
-               (call-with-input-file pth zo-parse))))
+                (define zo (call-with-input-file pth zo-parse))
+                (if submod
+                    (extract-submod zo submod)
+                    zo))))
+
+(define (extract-submod zo submod)
+  (define m (compilation-top-code zo))
+  (struct-copy compilation-top
+               zo
+               [code (let loop ([m m])
+                       (if (and (pair? (mod-name m))
+                                (equal? submod (cdr (mod-name m))))
+                           m
+                           (or (ormap loop (mod-pre-submodules m))
+                               (ormap loop (mod-post-submodules m)))))]))
 
 (define (excluded? pth)
-  (set-member? (current-excluded-modules) (path->string pth)))
+  (and (path? pth)
+       (set-member? (current-excluded-modules) (path->string pth))))
 
 (define (get-nodep-module-code/index mpi phase)
   (define pth (mpi->path! mpi))
@@ -61,7 +76,9 @@
       (hash-ref! 
        MODULE-CACHE pth 
        (lambda ()
-         (define-values (base file dir?) (split-path pth))
+         (define-values (base file dir?) (split-path (if (path-string? pth)
+                                                         pth
+                                                         (cadr pth))))
          (define base-directory
            (if (path? base) 
                (path->complete-path base (current-directory))
@@ -73,8 +90,9 @@
               (parameterize ([current-load-relative-directory base-directory])
                 (path->comp-top
                  (build-compiled-path 
-                             base 
-                             (path-add-suffix file #".zo"))))
+                  base 
+                  (path-add-suffix file #".zo"))
+                 (and (pair? pth) (cddr pth))))
               pth
               phase)))
          (when (and phase (zero? phase))