1 files changed, 3 insertions, 0 deletions
diff --git a/src/expl.sml b/src/expl.sml
index 87ca990e..b3bcf96b 100644
--- a/src/expl.sml
+++ b/src/expl.sml
@@ -33,6 +33,7 @@ datatype kind' =
          KType
        | KArrow of kind * kind
        | KName
+       | KUnit
        | KRecord of kind
 
 withtype kind = kind' located
@@ -54,6 +55,8 @@ datatype con' =
        | CConcat of con * con
        | CFold of kind * kind
 
+       | CUnit
+
 withtype con = con' located
 
 datatype exp' =