diff --git a/collects/tests/web-server/dispatchers/filesystem-map-test.rkt b/collects/tests/web-server/dispatchers/filesystem-map-test.rkt
index f3ed284718..d948241563 100644
--- a/collects/tests/web-server/dispatchers/filesystem-map-test.rkt
+++ b/collects/tests/web-server/dispatchers/filesystem-map-test.rkt
@@ -1,6 +1,7 @@
 #lang racket/base
 (require rackunit
          net/url
+         racket/list
          web-server/private/util
          racket/runtime-path
          web-server/dispatchers/filesystem-map)
@@ -18,23 +19,23 @@
 (define test-filter-map (filter-url->path #rx"\\.(ss|scm|rkt)$" test-map))
 (define test-filter-valid-map (filter-url->path #rx"\\.(ss|scm|rkt)$" test-valid-map))
 
-(define (test-url->path 
+(define (test-url->path
          url->path file
-         #:url-string 
+         #:url-string
          [url-string
           (format "http://test.com/~a" (path->string file))]
          #:expected
          [expected file])
   (define vs
     (call-with-values
-     (lambda () (url->path (string->url url-string)))
-     (lambda vs vs)))
+        (lambda () (url->path (string->url url-string)))
+      (lambda vs vs)))
   (check-equal? vs (list (build-path base-dir expected) (explode-path* expected))))
 
 (define filesystem-map-tests
   (test-suite
    "Filesystem Map"
-   
+
    (test-suite
     "url->path"
     (test-case "Simple case"
@@ -44,9 +45,12 @@
                                #:url-string "http://test.com/dispatchers/filesystem-map.rkt;foo"))
     (test-case "Strips out bad '..'s"
                (check-exn exn:fail? (λ () (test-map (string->url "http://test.com/../../dispatchers/filesystem-map.rkt")))))
+    (test-case "Handles // okay"
+               (check-equal? (second (call-with-values (λ () (test-map (string->url "http://test.com//dispatchers/filesystem-map.rkt"))) list))
+                             (list 'same (build-path "dispatchers") (build-path "filesystem-map.rkt"))))
     (test-case "Leaves in good '..'s"
                (test-url->path test-map (build-path "dispatchers/../dispatchers/filesystem-map.rkt"))))
-   
+
    (test-suite
     "url->valid-path"
     (test-suite
@@ -57,14 +61,14 @@
                 (test-url->path test-valid-map (build-path "dispatchers/filesystem-map.rkt")
                                 #:url-string "http://test.com/dispatchers/filesystem-map.rkt;foo"))
      (test-case "Strips out bad '..'s"
-               (check-exn exn:fail? (λ () (test-valid-map (string->url "http://test.com/../../dispatchers/filesystem-map.rkt")))))
+                (check-exn exn:fail? (λ () (test-valid-map (string->url "http://test.com/../../dispatchers/filesystem-map.rkt")))))
      (test-case "Leaves in good '..'s"
                 (test-url->path test-valid-map (build-path "dispatchers/../dispatchers/filesystem-map.rkt"))))
     (test-case "Finds valid path underneath"
                (test-url->path test-valid-map (build-path "dispatchers/filesystem-map.rkt/not-a-file")
                                #:expected (build-path "dispatchers/filesystem-map.rkt"))))
-   
-   
+
+
    (test-suite
     "filter-url->path"
     (test-case "Allows right suffix"
@@ -84,4 +88,3 @@
     (test-case "Allows content after w/ valid"
                (test-url->path test-filter-valid-map (build-path "dispatchers/filesystem-map.rkt/extra/info")
                                #:expected (build-path "dispatchers/filesystem-map.rkt"))))))
-
diff --git a/collects/web-server/dispatchers/filesystem-map.rkt b/collects/web-server/dispatchers/filesystem-map.rkt
index f016053e8f..4588610cbd 100644
--- a/collects/web-server/dispatchers/filesystem-map.rkt
+++ b/collects/web-server/dispatchers/filesystem-map.rkt
@@ -71,8 +71,11 @@
 (define ((make-url->path base) u)
   (define nbase (path->complete-path base))
   (define path-from-url
-    (map path/param-path 
-         (url-path u)))
+    (for/list ([p/p (in-list (url-path u))])
+      (match (path/param-path p/p)
+        ["" 'same]
+        [".." 'up]
+        [x x])))
   (unless (restrict path-from-url)
     (error 'url->path "Illegal path: ~e outside base: ~e" 
            path-from-url