diff --git a/src/formulare/core.clj b/src/formulare/core.clj
index 3feb134..de3fb73 100644
--- a/src/formulare/core.clj
+++ b/src/formulare/core.clj
@@ -138,6 +138,6 @@
 (spec/fdef render-widgets
   :args (spec/cat :form-def ::form
                   :values (spec/or :no-values nil?
-                                   :values map?))
-  :ret map?)
+                                   :values map?)
+                  :req map?))
 (spectest/instrument `render-widgets)