diff --git a/pipeline/cb-schema/json.ml b/pipeline/cb-schema/json.ml
index 006bc068..15471445 100644
--- a/pipeline/cb-schema/json.ml
+++ b/pipeline/cb-schema/json.ml
@@ -7,9 +7,7 @@ type t =
   | `Float of float
   | `String of string
   | `Assoc of (string * t) list
-  | `List of t list
-  | `Tuple of t list
-  | `Variant of string * t option ]
+  | `List of t list ]
 
 let error key value_type value =
   match value with
diff --git a/pipeline/cb-schema/schema.ml b/pipeline/cb-schema/schema.ml
index 8f9810e8..131aa0ae 100644
--- a/pipeline/cb-schema/schema.ml
+++ b/pipeline/cb-schema/schema.ml
@@ -222,7 +222,7 @@ let result_of_json t lines =
 let of_json t =
   let lines =
     match Json.get_opt "lines" t with
-    | `Tuple [ `Int start; `Int finish ] -> [ (start, finish) ]
+    | `List [ `Int start; `Int finish ] -> [ (start, finish) ]
     | _ -> []
   in
   {