Welcome to the CHICKEN Scheme pasting service

diff --git a/tests/test-create-temporary-file.scm b/tests/test-create-temporary-file.scm
index 67e664c3..45f743b4 100644
--- a/tests/test-create-temporary-file.scm
+++ b/tests/test-create-temporary-file.scm
@@ -1,6 +1,18 @@
 (import (chicken file)
+        (chicken format)
         (chicken pathname)
-        (chicken process-context))
+        (chicken process-context)
+        (chicken process-context posix)
+        (chicken time))
+
+(define base-dir
+  (make-pathname (current-directory)
+                 (sprintf "tmp-~a~a~a"
+                          (current-seconds)
+                          (current-process-id)
+                          (current-process-milliseconds))))
+
+(create-directory base-dir)
 
 (define (with-environment-variable var val thunk)
   (let ((old-val (get-environment-variable var)))
@@ -17,17 +29,16 @@
 ;; Assert that changes to the environment variables used by
 ;; create-temporary-file and create-temporary-directory get used (see
 ;; https://bugs.call-cc.org/ticket/1830).
-;;
-;; Here the use of "" as value of TMPDIR is because
-;; (pathname-directory (make-pathname "" filename)) => #f
-(with-environment-variable "TMPDIR" ""
+(with-environment-variable "TMPDIR" base-dir
   (lambda ()
     (let ((tmp (create-temporary-file)))
       (delete-file tmp)
-      (assert (not (pathname-directory tmp))))))
+      (assert (string=? base-dir (pathname-directory tmp))))))
 
-(with-environment-variable "TMPDIR" ""
+(with-environment-variable "TMPDIR" base-dir
   (lambda ()
     (let ((tmp (create-temporary-directory)))
       (delete-directory tmp)
-      (assert (not (pathname-directory tmp))))))
+      (assert (string=? base-dir (pathname-directory tmp))))))
+
+(delete-directory base-dir #t)