diff --git a/compiler/tests-sourcemap/dump_sourcemap.ml b/compiler/tests-sourcemap/dump_sourcemap.ml
index 0ee2388520..bf6b8ba46f 100644
--- a/compiler/tests-sourcemap/dump_sourcemap.ml
+++ b/compiler/tests-sourcemap/dump_sourcemap.ml
@@ -72,7 +72,7 @@ let print_mapping lines ~line_offset (sm : Source_map.t) =
           | _ -> ()))
 
 let print_sourcemap lines = function
-  | `Standard sm -> print_mapping ~offset:0 lines sm
+  | `Standard sm -> print_mapping ~line_offset:0 lines sm
   | `Index l ->
       List.iter
         l.Source_map.Index.sections
diff --git a/tools/sourcemap/jsoo_sourcemap.ml b/tools/sourcemap/jsoo_sourcemap.ml
index 571a06384b..51587506af 100644
--- a/tools/sourcemap/jsoo_sourcemap.ml
+++ b/tools/sourcemap/jsoo_sourcemap.ml
@@ -45,4 +45,7 @@ let () =
     | _ -> failwith "unable to find sourcemap"
   in
   let sm = Js_of_ocaml_compiler.Source_map.of_string content in
-  print_endline (Js_of_ocaml_compiler.Source_map.to_string sm)
+  print_endline
+    (match sm with
+    | `Standard sm -> Js_of_ocaml_compiler.Source_map.to_string sm
+    | `Index sm -> Js_of_ocaml_compiler.Source_map.Index.to_string sm)