diff --git a/networks.rkt b/networks.rkt
index 27dc3af..beaac66 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -275,7 +275,7 @@
 
 ;;; Build an update function from an update function form.
 (define (update-function-form->update-function form)
-  (λ (s) (eval-with s form)))
+  (λ (s) (eval1-with s form)))
 
 (module+ test
   (test-case "update-function-form->update-function"