diff --git a/src/expand.clj b/src/expand.clj
index 1271909..905716b 100644
--- a/src/expand.clj
+++ b/src/expand.clj
@@ -210,7 +210,7 @@
   (transcribe* 0 unification (s/conform ::template template)))
 
 (comment
-  (transcribe-transformer scheme-and '(and 1)))
+  (transcribe-transformer scheme-and '(and 1 2)))
 
 (defn transcribe-transformer [trans datum]
   (some (fn [{:keys [pattern template]}]
@@ -317,8 +317,7 @@
                     (for [[x rhs] bindings]
                       (bind-lexical
                        [x scopes*]
-                       [:macro (->> (expand rhs env symtable-ref scopes)
-                                    (s/conform ::transformer))]
+                       [:macro (expand rhs env symtable-ref scopes)]
                        symtable-ref)))]
     (concat (list 'let-syntax bindings)
             (for [e body]
@@ -326,8 +325,9 @@
 
 (defmethod expand-primitive 'syntax-rules
   [datum _ env symtable-ref scopes]
-  (assert (s/valid? ::prim-syntax-rules datum))
-  datum)
+  (let [r (s/conform ::prim-syntax-rules datum)]
+    (assert (not (s/invalid? r)))
+    r))
 
 (defn expand
   ([datum]
@@ -346,8 +346,6 @@
      (match (lookup [f scopes] env @symtable-ref)
        [:primitive prim] (expand-primitive
                           datum prim env symtable-ref scopes)
-       [:macro trans] (todo "trans %s" (->> trans
-                                            (s/conform ::prim-syntax-rules)
-                                            pr-str))
+       [:macro trans] (todo "trans %s" (->> (pr-str trans)))
        _ (cons (expand f env symtable-ref scopes)
                (map #(expand % env symtable-ref scopes) xs))))))