diff --git a/src/stages/common/helpers.ml b/src/stages/common/helpers.ml
index d498a1712..5dba263b8 100644
--- a/src/stages/common/helpers.ml
+++ b/src/stages/common/helpers.ml
@@ -28,6 +28,8 @@ let bind_fold_lmap f init (lmap:_ LMap.t) =
 
 let bind_map_lmap f map = bind_lmap (LMap.map f map)
 let bind_map_cmap f map = bind_cmap (CMap.map f map)
+let bind_map_lmapi f map = bind_lmap (LMap.mapi f map)
+let bind_map_cmapi f map = bind_cmap (CMap.mapi f map)
 
 let range i j =
   let rec aux i j acc = if i >= j then acc else aux i (j-1) (j-1 :: acc) in
diff --git a/src/stages/common/helpers.mli b/src/stages/common/helpers.mli
index 69efa24eb..d5e388e36 100644
--- a/src/stages/common/helpers.mli
+++ b/src/stages/common/helpers.mli
@@ -19,3 +19,12 @@ val is_tuple_lmap : 'a Types.label_map -> bool
 val get_pair :
            'a Types.label_map ->
            (('a * 'a) * 'b list, unit -> Trace.error) result
+
+
+
+val bind_map_lmapi : 
+  (Types.label -> 'a -> ('b * 'c list, 'd) result) ->
+  'a Types.label_map -> ('b Types.label_map * 'c list, 'd) result
+val bind_map_cmapi : 
+  (Types.constructor' -> 'a -> ('b * 'c list, 'd) result) ->
+  'a Types.constructor_map -> ('b Types.constructor_map * 'c list, 'd) result