diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index 53162b3f9a..73d4f6e2eb 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -472,9 +472,9 @@ for PATH."
           (match (read p)
             (('narinfo ('version 2)
                        ('cache-uri cache-uri)
-                       ('date date) ('ttl _) ('value #f))
+                       ('date date) ('ttl ttl) ('value #f))
              ;; A cached negative lookup.
-             (if (obsolete? date now %narinfo-negative-ttl)
+             (if (obsolete? date now ttl)
                  (values #f #f)
                  (values #t #f)))
             (('narinfo ('version 2)
@@ -722,7 +722,7 @@ was found."
           (match (read port)
             (('narinfo ('version 2) ('cache-uri uri)
                        ('date date) ('ttl ttl) ('value #f))
-             (+ date %narinfo-negative-ttl))
+             (+ date ttl))
             (('narinfo ('version 2) ('cache-uri uri)
                        ('date date) ('ttl ttl) ('value value))
              (+ date ttl))