diff --git a/src/bin/cli.ml b/src/bin/cli.ml
index 11777b504..fd3fa05be 100644
--- a/src/bin/cli.ml
+++ b/src/bin/cli.ml
@@ -37,6 +37,14 @@ let syntax =
     info ~docv ~doc ["syntax" ; "s"] in
   value @@ opt string "auto" info
 
+let bigmap =
+  let open Arg in
+  let info =
+    let docv = "BIGMAP" in
+    let doc = "$(docv) is necessary when your storage embeds a big_map." in
+    info ~docv ~doc ["bigmap"] in
+  value @@ flag info
+
 let amount =
   let open Arg in
   let info =
@@ -76,30 +84,30 @@ let compile_parameter =
   (term , Term.info ~docs cmdname)
 
 let compile_storage =
-  let f source entry_point expression syntax =
+  let f source entry_point expression syntax bigmap =
     toplevel @@
     let%bind value =
       trace (simple_error "compile-storage") @@
-      Ligo.Run.compile_contract_storage source entry_point expression (Syntax_name syntax) in
+      Ligo.Run.compile_contract_storage ?bigmap:(Some bigmap) source entry_point expression (Syntax_name syntax) in
     Format.printf "%s\n" value;
     ok ()
   in
   let term =
-    Term.(const f $ source 0 $ entry_point 1 $ expression "STORAGE" 2 $ syntax) in
+    Term.(const f $ source 0 $ entry_point 1 $ expression "STORAGE" 2 $ syntax $ bigmap) in
   let cmdname = "compile-storage" in
   let docs = "Subcommand: compile an initial storage in ligo syntax to a michelson expression. The resulting michelson expression can be passed as an argument in a transaction which originates a contract. See `ligo " ^ cmdname ^ " --help' for a list of options specific to this subcommand." in
   (term , Term.info ~docs cmdname)
 
 let dry_run =
-  let f source entry_point storage input amount syntax =
+  let f source entry_point storage input bigmap amount syntax =
     toplevel @@
     let%bind output =
-      Ligo.Run.run_contract ~amount source entry_point storage input (Syntax_name syntax) in
+      Ligo.Run.run_contract ~bigmap ~amount source entry_point storage input (Syntax_name syntax) in
     Format.printf "%a\n" Ast_simplified.PP.expression output ;
     ok ()
   in
   let term =
-    Term.(const f $ source 0 $ entry_point 1 $ expression "PARAMETER" 2 $ expression "STORAGE" 3 $ amount $ syntax) in
+    Term.(const f $ source 0 $ entry_point 1 $ expression "PARAMETER" 2 $ expression "STORAGE" 3 $ bigmap $ amount $ syntax) in
   let cmdname = "dry-run" in
   let docs = "Subcommand: run a smart-contract with the given storage and input." in
   (term , Term.info ~docs cmdname)
diff --git a/src/contracts/big_map.ligo b/src/contracts/big_map.ligo
index b5f6d44c5..461c2c206 100644
--- a/src/contracts/big_map.ligo
+++ b/src/contracts/big_map.ligo
@@ -5,6 +5,7 @@ function main(const p : unit; const s : storage_) : list(operation) * storage_ i
   var toto : option (int) := Some(0);
   block {
     toto := r[23];
+    r[2] := 444;
     s.0 := r;
   }
   with ((nil: list(operation)), s)
diff --git a/src/main/run_source.ml b/src/main/run_source.ml
index 10904914a..71f7d3b55 100644
--- a/src/main/run_source.ml
+++ b/src/main/run_source.ml
@@ -46,6 +46,17 @@ include struct
     ok ()
 end
 
+let transpile_value_literals 
+    (e:Ast_typed.annotated_expression) : (Mini_c.value * _) result =
+  let%bind (_ , ty) =
+    let open Transpiler in
+    let (f , _) = functionalize e in
+    let%bind main = translate_main f e.location in
+    ok main
+  in
+  let%bind lit = Run_typed.convert_to_literals e in
+  ok (lit , snd ty)
+
 let transpile_value
     (e:Ast_typed.annotated_expression) : (Mini_c.value * _) result =
   let%bind (f , ty) =
@@ -196,8 +207,20 @@ let compile_contract_parameter : string -> string -> string -> s_syntax -> strin
   in
   ok expr
 
+(* Replace occurrences of E_map with E_big_map in the AST  *)
+let rec transform_map_to_big_map (e: Ast_simplified.expression) : Ast_simplified.expression result = 
+  let open Ast_simplified in
+  match e.wrap_content with
+  | E_tuple [fst;snd] ->
+    let%bind tr_fst = transform_map_to_big_map fst in
+    let new_tuple = Location.wrap (E_tuple [tr_fst;snd]) in
+    ok @@ new_tuple
+  | E_map lst ->
+    let tr_map = Location.wrap (E_big_map lst) in
+    ok @@ tr_map
+  | _ -> fail @@ simple_error "can not replace map with big_map"
 
-let compile_contract_storage : string -> string -> string -> s_syntax -> string result = fun source_filename entry_point expression syntax ->
+let compile_contract_storage ?(bigmap = false) source_filename entry_point expression syntax : string result =
   let%bind syntax = syntax_to_variant syntax (Some source_filename) in
   let%bind (program , storage_tv) =
     let%bind simplified = parsify syntax source_filename in
@@ -212,6 +235,7 @@ let compile_contract_storage : string -> string -> string -> s_syntax -> string
   in
   let%bind expr =
     let%bind simplified = parsify_expression syntax expression in
+    let%bind simplified = if bigmap then transform_map_to_big_map simplified else ok @@ simplified in
     let%bind typed =
       let env =
         let last_declaration = Location.unwrap List.(hd @@ rev program) in
@@ -225,7 +249,7 @@ let compile_contract_storage : string -> string -> string -> s_syntax -> string
       Ast_typed.assert_type_value_eq (storage_tv , typed.type_annotation) in
     let%bind (mini_c , mini_c_ty) =
       trace (simple_error "transpiling expression") @@
-      transpile_value typed in
+      (if bigmap then transpile_value_literals typed else transpile_value typed) in
     let%bind michelson =
       trace (simple_error "compiling expression") @@
       Compiler.translate_value mini_c mini_c_ty in
@@ -249,7 +273,7 @@ let type_file ?(debug_simplify = false) ?(debug_typed = false)
     )) ;
   ok typed
 
-let run_contract ?amount source_filename entry_point storage input syntax =
+let run_contract ?(bigmap = false) ?amount source_filename entry_point storage input syntax =
   let%bind syntax = syntax_to_variant syntax (Some source_filename) in
   let%bind typed =
     type_file syntax source_filename in
@@ -257,11 +281,12 @@ let run_contract ?amount source_filename entry_point storage input syntax =
     parsify_expression syntax storage in
   let%bind input_simpl =
     parsify_expression syntax input in
+  let%bind input_simpl = if bigmap then transform_map_to_big_map input_simpl else ok @@ input_simpl in
   let options =
     let open Proto_alpha_utils.Memory_proto_alpha in
     let amount = Option.bind (fun amount -> Protocol.Alpha_context.Tez.of_string amount) amount in
     (make_options ?amount ()) in
-  Run_simplified.run_simplityped ~options typed entry_point (Ast_simplified.e_pair storage_simpl input_simpl)
+  Run_simplified.run_simplityped ?input_to_value:(Some bigmap) ~options typed entry_point (Ast_simplified.e_pair storage_simpl input_simpl)
 
 let run_function ?amount source_filename entry_point parameter syntax =
   let%bind syntax = syntax_to_variant syntax (Some source_filename) in
diff --git a/src/main/run_typed.ml b/src/main/run_typed.ml
index 9c5157c27..aef51cd56 100644
--- a/src/main/run_typed.ml
+++ b/src/main/run_typed.ml
@@ -30,7 +30,7 @@ let evaluate_typed
     Transpiler.untranspile result typed_main.type_annotation in
   ok typed_result
 
-(* returns a big_map if any *)
+(* returns a big_map if any. used to reconstruct the map from the diff when uncompiling *)
 let rec fetch_big_map (v: Mini_c.value) : Mini_c.value option =
   match v with
   | D_pair (l , r) ->
@@ -40,7 +40,7 @@ let rec fetch_big_map (v: Mini_c.value) : Mini_c.value option =
     | None -> fetch_big_map r 
     end
   | D_big_map _ as bm -> Some bm 
-  | _ -> let () = Printf.printf "lal\n" in None
+  | _ -> None
 
 (* try to convert expression to a literal *)
 let rec exp_to_value (exp: Mini_c.expression) : Mini_c.value result =
@@ -67,6 +67,7 @@ let rec exp_to_value (exp: Mini_c.expression) : Mini_c.value result =
       let%bind fstl = exp_to_value fst in
       let%bind sndl = exp_to_value snd in
       ok @@ D_pair (fstl , sndl)
+    | E_constant ("UNIT", _) -> ok @@ D_unit
     | E_constant ("UPDATE", _) ->
       let rec handle_prev upd =
         match upd.content with