diff --git a/src/Category.hs b/src/Category.hs
index 93e9b1cff..b6ae4ded2 100644
--- a/src/Category.hs
+++ b/src/Category.hs
@@ -41,6 +41,8 @@ data Category
   | Assignment
   -- | A member access expression.
   | MemberAccess
+  -- | An if expression.
+  | If
   -- | A non-standard category, which can be used for comparability.
   | Other Text
   deriving (Eq, Show, Ord)