diff --git a/src/Syntax.hs b/src/Syntax.hs
index d06897412..48d1c965f 100644
--- a/src/Syntax.hs
+++ b/src/Syntax.hs
@@ -60,6 +60,7 @@ data Syntax
   | DoWhile { doWhileBody :: f, doWhileExpr :: f }
   | While { whileExpr :: f, whileBody :: f }
   | Return (Maybe f)
+  | Class f (Maybe f) [f]
   deriving (Eq, Foldable, Functor, Generic, Generic1, Mergeable, Ord, Show, Traversable)