diff --git a/pkgs/distro-build-pkgs/distro-build-server/pack-and-catalog.rkt b/pkgs/distro-build-pkgs/distro-build-server/pack-and-catalog.rkt
index f369b2a06e..87a15feee0 100644
--- a/pkgs/distro-build-pkgs/distro-build-server/pack-and-catalog.rkt
+++ b/pkgs/distro-build-pkgs/distro-build-server/pack-and-catalog.rkt
@@ -102,6 +102,7 @@
                ;; Use a constant timestamp so that the checksum does
                ;; not depend on timestamps:
                #:timestamp 1359788400
+               #:utc-timestamps? #t
                #:system-type 'unix))
       (delete-directory/files tmp-dir)
       (call-with-output-file*