diff --git a/networks.rkt b/networks.rkt
index d093dac..646763c 100644
--- a/networks.rkt
+++ b/networks.rkt
@@ -345,7 +345,7 @@
 (define (list-syntactic-interactions nf x)
   (set-intersect
    (extract-symbols (hash-ref (network-form-forms nf) x))
-   (hash-keys nf)))
+   (hash-keys (network-form-forms nf))))
 
 (module+ test
   (test-case "list-syntactic-interactions"