diff --git a/guix/scripts/substitute.scm b/guix/scripts/substitute.scm
index 1ab18d0260..efbcfe78ca 100755
--- a/guix/scripts/substitute.scm
+++ b/guix/scripts/substitute.scm
@@ -607,10 +607,11 @@ (define (handle-narinfo-response request response port result)
                            #f ttl)
            (update-progress!)
            result))
-        (else                                      ; transient failure
+        (else                                      ; transient failure: 504...
          (if len
              (get-bytevector-n port len)
              (read-to-eof port))
+         (update-progress!)
          result))))
 
   (define (do-fetch uri port)