diff --git a/src/alumbra/spec/canonical_operation.clj b/src/alumbra/spec/canonical_operation.clj
index 21b203d..c4f6383 100644
--- a/src/alumbra/spec/canonical_operation.clj
+++ b/src/alumbra/spec/canonical_operation.clj
@@ -55,6 +55,7 @@
 (defmethod field-spec :object
   [_]
   (s/keys :req-un [:alumbra/non-null?
+                   :alumbra/type-name
                    ::field-type
                    ::selection-set]))