diff --git a/scheme/httpd/surflets/profile.scm b/scheme/httpd/surflets/profile.scm
index 96c17a2..e2a11c5 100644
--- a/scheme/httpd/surflets/profile.scm
+++ b/scheme/httpd/surflets/profile.scm
@@ -147,7 +147,7 @@
 ;; for a simple 2D plot, readable by GNUPLOT (external program, not
 ;; part of SUnet, http://www.gnuplot.info/)
 (define (write-gnuplot-data-file output-file selector space-info-list)
-  (let ((out (open-output-file output-file)))
+  (let ((out (open-output-file output-file (bitwise-ior open/create open/truncate))))
     (display "# generated by profile.scm\n" out)
     (let loop ((count 0)
 	       (space-info-list space-info-list))