diff --git a/infer/src/absint/FormalMap.ml b/infer/src/absint/FormalMap.ml
index 1d00943b5..354d8cb67 100644
--- a/infer/src/absint/FormalMap.ml
+++ b/infer/src/absint/FormalMap.ml
@@ -40,3 +40,5 @@ let get_formal_base index t =
   |> Option.map ~f:fst
 
 let get_formals_indexes = AccessPath.BaseMap.bindings
+
+let pp = AccessPath.BaseMap.pp ~pp_value:Int.pp
diff --git a/infer/src/absint/FormalMap.mli b/infer/src/absint/FormalMap.mli
index 2461a2a45..8c83b3f95 100644
--- a/infer/src/absint/FormalMap.mli
+++ b/infer/src/absint/FormalMap.mli
@@ -31,3 +31,6 @@ val get_formal_base : int -> t -> AccessPath.base option
     linear in the size of the formal map *)
 
 val get_formals_indexes : t -> (AccessPath.base * int) list
+(** Get a list of (base * index) pairs. Note: these are sorted by base, not index *)
+
+val pp : F.formatter -> t -> unit