diff --git a/gnu/packages/onc-rpc.scm b/gnu/packages/onc-rpc.scm
index 4495622191..3928e80476 100644
--- a/gnu/packages/onc-rpc.scm
+++ b/gnu/packages/onc-rpc.scm
@@ -1,5 +1,5 @@
 ;;; GNU Guix --- Functional package management for GNU
-;;; Copyright © 2014, 2017, 2018 Ludovic Courtès <ludo@gnu.org>
+;;; Copyright © 2014, 2017, 2018, 2022 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2016 John Darrington <jmd@gnu.org>
 ;;; Copyright © 2017, 2018 Leo Famulari <leo@famulari.name>
 ;;; Copyright © 2018, 2021 Tobias Geerinckx-Rice <me@tobias.gr>
@@ -27,6 +27,7 @@ (define-module (gnu packages onc-rpc)
   #:use-module (guix licenses)
   #:use-module (guix packages)
   #:use-module (guix download)
+  #:use-module (guix gexp)
   #:use-module (guix git-download)
   #:use-module (gnu packages)
   #:use-module (gnu packages autotools)
@@ -84,9 +85,9 @@ (define-public libtirpc/hurd
      (substitute-keyword-arguments (package-arguments libtirpc)
        ((#:configure-flags flags ''())
         ;; When cross-building the target system's krb5-config should be used.
-        `(list (string-append "ac_cv_prog_KRB5_CONFIG="
-                              (assoc-ref %build-inputs "mit-krb5")
-                              "/bin/krb5-config")))))))
+        #~(list (string-append "ac_cv_prog_KRB5_CONFIG="
+                               #$(this-package-input "mit-krb5")
+                               "/bin/krb5-config")))))))
 
 (define libtirpc/fixed
   (package