diff --git a/collects/mzlib/sandbox.ss b/collects/mzlib/sandbox.ss
index 9515b8a8c3..27f77db42d 100644
--- a/collects/mzlib/sandbox.ss
+++ b/collects/mzlib/sandbox.ss
@@ -509,8 +509,12 @@
              [reqs (cond [(not requires) '()]
                          [(not (list? requires))
                           (error 'make-evaluator "bad requires: ~e" requires)]
-                         [else (map (lambda (r) (if (pair? r) r `(file ,r)))
-                                    requires)])])
+                         [else
+                          (map (lambda (r)
+                                 (if (or (pair? r) (symbol? r))
+                                   r
+                                   `(file ,(path->string (simplify-path* r)))))
+                               requires)])])
          (make-evaluator* (init-for-language lang)
                           (require-perms lang reqs)
                           (lambda () (build-program lang reqs input-program))))]
diff --git a/collects/tests/mzscheme/sandbox.ss b/collects/tests/mzscheme/sandbox.ss
index 5d159cca68..ccda20c931 100644
--- a/collects/tests/mzscheme/sandbox.ss
+++ b/collects/tests/mzscheme/sandbox.ss
@@ -165,7 +165,8 @@
    (when (directory-exists? "/tmp") ; non-collects place to play with
      (let* ([mzlib    (path->string (collection-path "mzlib"))]
             [list-lib (path->string (build-path mzlib "list.ss"))]
-            [test-lib "/tmp/sandbox-test.ss"])
+            [test-lib (path->string (path->complete-path ; <- for windows
+                                     "/tmp/sandbox-test.ss"))])
        (t --top--
           (set! ev (make-evaluator 'mzscheme '()))
           --eval--
@@ -203,10 +204,15 @@
           (directory-list "/tmp") =err> "file access denied"
           --top--
           ;; explicitly allow access to /tmp
-          (set! ev (parameterize ([sandbox-path-permissions
-                                   `((read #rx#"^/tmp(?:/|$)")
-                                     ,@(sandbox-path-permissions))])
-                     (make-evaluator 'mzscheme '())))
+          (set! ev (let ([rx (if (eq? 'windows (system-type))
+                               ;; on windows this will have a drive letter
+                               #rx#"^[a-zA-Z]:[/\\]tmp(?:[/\\]|$)"
+                               #rx#"^/tmp(?:/|$)")])
+                     (parameterize ([sandbox-path-permissions
+                                     ;; allow all `/tmp' paths for windows
+                                     `((read ,rx)
+                                       ,@(sandbox-path-permissions))])
+                       (make-evaluator 'mzscheme '()))))
           --eval--
           (length (with-input-from-file ,test-lib read)) => 5
           (list? (directory-list "/tmp"))