1 files changed, 2 insertions, 1 deletions
diff --git a/src/source.sml b/src/source.sml
index 9ea1ea20..2246399b 100644
--- a/src/source.sml
+++ b/src/source.sml
@@ -51,12 +51,13 @@ datatype con' =
 
        | CVar of string list * string
        | CApp of con * con
-       | CAbs of string * kind * con
+       | CAbs of string * kind option * con
 
        | CName of string
 
        | CRecord of (con * con) list
        | CConcat of con * con
+       | CFold
 
        | CWild of kind