diff --git a/guix/gexp.scm b/guix/gexp.scm
index 38114f8863..9fdb7a30be 100644
--- a/guix/gexp.scm
+++ b/guix/gexp.scm
@@ -181,7 +181,8 @@ As a result, the S-expression will be approximate if GEXP has references."
                          (#true
                           ;; Simply returning 'thing' won't work in some
                           ;; situations; see 'write-gexp' below.
-                          '(*approximate*))))))
+                          '(*approximate*))))
+                  (($ <gexp-output>) '(*approximate*))))
               (gexp-references gexp))))
 
 (define (write-gexp gexp port)
diff --git a/tests/gexp.scm b/tests/gexp.scm
index 61ed5bc02d..c80ca13fab 100644
--- a/tests/gexp.scm
+++ b/tests/gexp.scm
@@ -148,6 +148,11 @@
          (null? (gexp-inputs exp))
          (gexp->sexp* exp))))
 
+(test-equal "gexp->approximate-sexp, outputs"
+  '(list 'out:foo (*approximate*) 'out:bar (*approximate*))
+  (gexp->approximate-sexp
+   #~(list 'out:foo #$output:foo 'out:bar #$output:bar)))
+
 (test-equal "unquote"
   '(display `(foo ,(+ 2 3)))
   (let ((exp (gexp (display `(foo ,(+ 2 3))))))