diff --git a/gnu/packages/tls.scm b/gnu/packages/tls.scm
index c178806805..a4e754e27f 100644
--- a/gnu/packages/tls.scm
+++ b/gnu/packages/tls.scm
@@ -376,10 +376,10 @@ required structures.")
             (let* ((out #$output)
                    (lib (string-append out "/lib")))
               ;; It's not a shebang so patch-source-shebangs misses it.
+              ;; Don't use (assoc-ref %build-inputs "coreutils"), as
+              ;; %build-inputs is not defined when cross-compiling.
               (substitute* "config"
-                (("/usr/bin/env")
-                 (string-append (assoc-ref %build-inputs "coreutils")
-                                "/bin/env")))
+                (("/usr/bin/env") (which "env")))
               (invoke #$@(if (%current-target-system)
                              #~("./Configure")
                              #~("./config"))