diff --git a/gnu/packages/embedded.scm b/gnu/packages/embedded.scm
index 6f09c8f353..db9d518b17 100644
--- a/gnu/packages/embedded.scm
+++ b/gnu/packages/embedded.scm
@@ -830,7 +830,7 @@ (define-public binutils-vc4
              (lambda _
                (substitute* "opcodes/Makefile.in"
                  (("guile\\{,-\\}1.8") "guile"))
-               (zero? (system* "which" "guile")))))))
+               (invoke "which" "guile"))))))
       (native-inputs
        `(("cgen"
           ,(origin