diff --git a/gnu/packages/engineering.scm b/gnu/packages/engineering.scm
index 92745852d..1d686271d 100644
--- a/gnu/packages/engineering.scm
+++ b/gnu/packages/engineering.scm
@@ -1456,9 +1456,10 @@ parallel computing platforms.  It also supports serial execution.")
                (("-lm") "-lm FREEHDL/lib/freehdl/libieee.la"))
              #t))
          (add-after 'patch-gvhdl 'patch-freehdl-gennodes
-           (lambda _
+           (lambda* (#:key inputs #:allow-other-keys)
              (substitute* "freehdl/freehdl-gennodes.in"
-               (("guile") (which "guile"))
+               (("guile")
+                (string-append (assoc-ref inputs "guile") "/bin/guile"))
                (("\\(debug") ";(debug")
                (("\\(@ ") "(apply-emit")
                (("\\(@@ ") "(apply-mini-format"))
@@ -1476,6 +1477,8 @@ parallel computing platforms.  It also supports serial execution.")
          (add-after 'install-scripts 'make-wrapper
            (lambda* (#:key inputs outputs #:allow-other-keys)
              (let ((out (assoc-ref outputs "out")))
+               ;; 'gvhdl' invokes the C compiler directly, so hard-code its
+               ;; file name.
                (wrap-program (string-append out "/bin/gvhdl")
                  `("CPLUS_INCLUDE_PATH" ":" prefix
                    (,(string-append (assoc-ref inputs "gcc-toolchain")