diff --git a/web/aslp.js b/web/aslp.js
index e312b86f..473018dd 100644
--- a/web/aslp.js
+++ b/web/aslp.js
@@ -85,3 +85,4 @@ const write = (isError) => s => {
 
 libASL_web.init(write(false), write(true));
 libASL_web.setDebugLevel(0);
+
diff --git a/web/dune b/web/dune
index 5daaee9b..87f4d3c7 100644
--- a/web/dune
+++ b/web/dune
@@ -3,7 +3,7 @@
   (modes js)
   (modules js)
   (libraries libASL libASL_web js_of_ocaml)
-  (js_of_ocaml (flags --debug-info --no-inline --sourcemap :standard \ --source-map-inline))
+  (js_of_ocaml (flags --sourcemap :standard \ --source-map-inline))
   (preprocess (pps js_of_ocaml-ppx))
   )
 
diff --git a/web/js.ml b/web/js.ml
index f6cab93e..e16fd656 100644
--- a/web/js.ml
+++ b/web/js.ml
@@ -5,8 +5,15 @@ let init input out err =
   Js_of_ocaml.Sys_js.set_channel_filler stdin input;
   ()
 
-let env = lazy (Option.get @@ LibASL.Arm_env.aarch64_evaluation_environment ())
-let denv = lazy (LibASL.Dis.build_env @@ Lazy.force env)
+let cachedenv : LibASL.Eval.Env.t option ref = ref None
+let uncachedenv = lazy (Option.get @@ LibASL.Arm_env.aarch64_evaluation_environment ())
+
+let env () =
+  match !cachedenv with
+  | Some x -> x
+  | None -> Lazy.force uncachedenv
+
+let denv = lazy (LibASL.Dis.build_env @@ env ())
 
 let print_pp = ref true
 
@@ -14,7 +21,7 @@ let pp_stmt () =
   if !print_pp then Asl_utils.pp_stmt else fun x -> Utils.to_string (Asl_parser_pp.pp_raw_stmt x)
 
 let dis (x: string) =
-  let stmts = LibASL.Dis.retrieveDisassembly Lazy.(force env) Lazy.(force denv) x in
+  let stmts = LibASL.Dis.retrieveDisassembly (env ()) Lazy.(force denv) x in
   List.iter
     (fun s -> print_endline @@ pp_stmt () s)
     stmts;
@@ -30,7 +37,9 @@ let () =
       (* TODO: support stdin from javascript for repl, possibly converting asli repl to lwt *)
       method init (out : string -> unit) (err : string -> unit) = init (fun () -> "") out err
 
-      method force = let _ = Lazy.force env and _ = Lazy.force denv in ()
+      method force = let env' = env () and _ = Lazy.force denv in fun () -> Js.bytestring @@ Marshal.to_string env' []
+      method cache (a: Js.js_string Js.t) = (cachedenv := Some (Marshal.from_string (Js.to_bytestring a) 0))
+      method uncache = (cachedenv := None)
       method dis (x: string) = dis x
       method setDebugLevel i = (LibASL.Dis.debug_level := i)
       method setPrettyPrint (x : bool) = (print_pp := x)