diff --git a/driver.lisp b/driver.lisp
index 94ae800956d550627700dc8231c9b3942fde68df..b2643ed2e2ff74c1bb7291ddbfaec5fb32c65aca 100644
--- a/driver.lisp
+++ b/driver.lisp
@@ -317,7 +317,7 @@ then returning the non-empty string value of the variable"
 (defun default-temporary-directory ()
   (flet ((f (s v d) (format nil "~A~A" (or (getenv v) d (error "No temporary directory!")) s)))
     (let ((dir (cond
-                 ((os-unix-p) (f #\/ "TMP" "/tmp"))
+                 ((os-unix-p) (f #\/ "TMPDIR" "/tmp"))
                  ((os-windows-p) (f #\\ "TEMP" nil))))
           #+mcl (dir (probe-posix dir)))
       (pathname dir))))