diff --git a/src/Brick/Widgets/Core.hs b/src/Brick/Widgets/Core.hs
index 5fcdac3..c7e08c6 100644
--- a/src/Brick/Widgets/Core.hs
+++ b/src/Brick/Widgets/Core.hs
@@ -4,6 +4,7 @@
 {-# LANGUAGE FlexibleInstances #-}
 {-# LANGUAGE OverloadedStrings #-}
 {-# LANGUAGE TypeFamilies #-}
+{-# LANGUAGE TypeOperators #-}
 -- | This module provides the core widget combinators and rendering
 -- routines. Everything this library does is in terms of these basic
 -- primitives.