diff --git a/resources/guix/gnuboot/packages/trisquel-netinst.scm b/resources/guix/gnuboot/packages/trisquel-netinst.scm
index 3095199..ba8465e 100644
--- a/resources/guix/gnuboot/packages/trisquel-netinst.scm
+++ b/resources/guix/gnuboot/packages/trisquel-netinst.scm
@@ -16,6 +16,7 @@
   #:use-module (gnu packages base)
   #:use-module (gnu packages bootloaders)
   #:use-module (gnu packages cdrom)
+  #:use-module (gnu packages check)
   #:use-module (gnu packages compression)
   #:use-module (gnu packages debian)
   #:use-module (gnu packages disk)
@@ -226,6 +227,7 @@ manually.")
     (native-inputs (list
                     coreutils
                     dosfstools
+                    libfaketime
                     mtools))
     (arguments
      (list
@@ -262,16 +264,18 @@ manually.")
                      "-n" "MEDIA"
                      "--invariant"
                      "preseed.img")
-             (invoke "mcopy"
+             (invoke "faketime" "@315532800" ; FAT epoch.
+                     "mcopy"
                      "-i" "preseed.img"
                      "-m"
                      "preseed.cfg"
                      "::/preseed.cfg")
-             (invoke "mcopy"
-                     "-i" "preseed.img"
-                     "-m"
-                     "shutdown-after-boot.service"
-                     "::/shutdown-after-boot.service")))
+             (invoke  "faketime" "@315532800" ; FAT epoch.
+                      "mcopy"
+                      "-i" "preseed.img"
+                      "-m"
+                      "shutdown-after-boot.service"
+                      "::/shutdown-after-boot.service")))
           (replace
            'install
            (lambda _
diff --git a/resources/trisquel/preseed.img.sha512 b/resources/trisquel/preseed.img.sha512
index cae4dce..8d83ac0 100644
--- a/resources/trisquel/preseed.img.sha512
+++ b/resources/trisquel/preseed.img.sha512
@@ -1 +1 @@
-f12a4a941afc9e24288481ed1b44fbfedf52d706e9e8aa01cfb26bf5ccd54ca52afe9ef5497faf2966ba730c1200d8b8691ebb87e6a75cd8966e0edd49bcb3c0  preseed.img
+d3dc630d1b3971a2f859ec2c72e1bc7b7ab59ea7c3932735868c9709567d58f9e7b4bd1af4ccb1e4f2931f974757cccb4ec2804baa446d540904de0cbf567a48  preseed.img