diff --git a/src/cdomains/arrayDomain_deprecated.ml b/src/cdomains/arrayDomain_deprecated.ml
index 717221ef..1cbb9576 100644
--- a/src/cdomains/arrayDomain_deprecated.ml
+++ b/src/cdomains/arrayDomain_deprecated.ml
@@ -10,7 +10,7 @@ type json = Yojson.Safe.t
 module Map = struct
     module Make (X: sig include Map.OrderedType val to_yojson : t -> json end) = struct
       include Map.Make (X)
-      let to_yojson poly_v x = [%to_yojson: (X.t * 'v) list] (bindings x)
+      let to_yojson poly_v x = [%to_yojson: (X.t * 'v) list] poly_v (bindings x)
     end
 end
 
@@ -1008,4 +1008,4 @@ struct
   let make i v = `Lifted (A.make i v)
 
   let pretty_diff () (x,y) = dprintf "%s: %a not leq %a" (name ()) pretty x pretty y
-end
\ No newline at end of file
+end
diff --git a/src/domains/mapDomain.ml b/src/domains/mapDomain.ml
index 69dc0d6b..e317eec8 100644
--- a/src/domains/mapDomain.ml
+++ b/src/domains/mapDomain.ml
@@ -53,7 +53,7 @@ module PMap (Domain: Groupable) (Range: Lattice.S) =
 struct
   module M = struct
     include Map.Make (Domain)
-    let to_yojson poly_v x = [%to_yojson: (Domain.t * 'v) list] (bindings x) (* TODO pull this into Prelude *)
+    let to_yojson poly_v x = [%to_yojson: (Domain.t * 'v) list] poly_v (bindings x) (* TODO pull this into Prelude *)
   end
 
   include Printable.Std