diff --git a/src/Category.hs b/src/Category.hs
index a66b12ed7..6f7b66a8e 100644
--- a/src/Category.hs
+++ b/src/Category.hs
@@ -288,6 +288,8 @@ instance Arbitrary Category where
     , pure Superclass
     , pure SingletonClass
     , pure ParameterDecl
+    , pure Default
+    , pure TypeDecl
     , Other <$> arbitrary
     ]