diff --git a/jscomp/bin/bsdep.ml b/jscomp/bin/bsdep.ml
index 2611f829e7..896fc065ed 100644
--- a/jscomp/bin/bsdep.ml
+++ b/jscomp/bin/bsdep.ml
@@ -31793,15 +31793,14 @@ let rec unsafe_mapper : Ast_mapper.mapper =
              payload)
           ->
           let strip s =
-            let len = String.length s in            
-            if s.[len - 1] = '_' then
-              String.sub s 0 (len - 1)
-            else s in                  
+            match s with 
+            | "_module" -> "module" 
+            | x -> x  in 
           begin match Ast_payload.as_ident payload with
             | Some {txt = Lident
-                        ("__filename"
+                        ( "__filename"
                         | "__dirname"
-                        | "module_"
+                        | "_module"
                         | "require" as name); loc}
               ->
               let exp =
@@ -31810,7 +31809,7 @@ let rec unsafe_mapper : Ast_mapper.mapper =
                      (strip name) ) in
               let typ =
                 Ast_comb.to_undefined_type loc @@                 
-                if name = "module_" then
+                if name = "_module" then
                   Typ.constr ~loc
                     { txt = Ldot (Lident "Node", "node_module") ;
                       loc} []   
diff --git a/jscomp/bin/bsppx.ml b/jscomp/bin/bsppx.ml
index 52238ab28f..19432e96dc 100644
--- a/jscomp/bin/bsppx.ml
+++ b/jscomp/bin/bsppx.ml
@@ -14977,15 +14977,14 @@ let rec unsafe_mapper : Ast_mapper.mapper =
              payload)
           ->
           let strip s =
-            let len = String.length s in            
-            if s.[len - 1] = '_' then
-              String.sub s 0 (len - 1)
-            else s in                  
+            match s with 
+            | "_module" -> "module" 
+            | x -> x  in 
           begin match Ast_payload.as_ident payload with
             | Some {txt = Lident
-                        ("__filename"
+                        ( "__filename"
                         | "__dirname"
-                        | "module_"
+                        | "_module"
                         | "require" as name); loc}
               ->
               let exp =
@@ -14994,7 +14993,7 @@ let rec unsafe_mapper : Ast_mapper.mapper =
                      (strip name) ) in
               let typ =
                 Ast_comb.to_undefined_type loc @@                 
-                if name = "module_" then
+                if name = "_module" then
                   Typ.constr ~loc
                     { txt = Ldot (Lident "Node", "node_module") ;
                       loc} []   
diff --git a/jscomp/bin/whole_compiler.ml b/jscomp/bin/whole_compiler.ml
index 440713838b..a2205f73ec 100644
--- a/jscomp/bin/whole_compiler.ml
+++ b/jscomp/bin/whole_compiler.ml
@@ -66008,7 +66008,7 @@ let const ct : t = Lconst ct
 *)
 let apply fn args loc status : t = 
   match fn with 
- (*| Lfunction {kind ; params ;  
+  | Lfunction {kind ; params ;  
                body = Lprim {primitive = 
                                (Pundefined_to_opt | Pnull_to_opt | Pnull_undefined_to_opt | Pis_null | Pis_null_undefined | Pjs_boolean_to_bool | Pjs_typeof ) as wrap;
                              args = [Lprim ({primitive; args = inner_args} as primitive_call)]
@@ -66020,7 +66020,7 @@ let apply fn args loc status : t =
         Lprim {primitive = wrap ; args = [Lprim { primitive_call with args ; loc = loc }] ; loc }
       | exception _ -> 
         Lapply { fn; args; loc; status }
-    end  *)
+    end  
   | Lfunction {kind ; params; 
                body = Lsequence (Lprim ({primitive; args = inner_args}as primitive_call), (Lconst _ as const )) }
     ->  
@@ -66203,16 +66203,16 @@ let prim ~primitive:(prim : primitive) ~args:(ll : t list) loc  : t =
         Lift.int (int_of_float (float_of_string a))
       (* | Pnegfloat -> Lift.float (-. a) *)
       (* | Pabsfloat -> Lift.float (abs_float a) *)
-      | Pstringlength, ( (Const_string (a)) ) 
+      | Pstringlength, Const_string a
         -> 
         Lift.int (String.length a)
       (* | Pnegbint Pnativeint, ( (Const_nativeint i)) *)
       (*   ->   *)
       (*   Lift.nativeint (Nativeint.neg i) *)
-      | Pnegbint Pint32, ( (Const_int32 a))
+      | Pnegbint Pint32, Const_int32 a
         -> 
         Lift.int32 (Int32.neg a)
-      | Pnegbint Pint64, ( (Const_int64 a))
+      | Pnegbint Pint64, Const_int64 a
         -> 
         Lift.int64 (Int64.neg a)
       | Pnot , Const_pointer (a,_) 
@@ -66413,6 +66413,7 @@ let lam_prim ~primitive:( p : Lambda.primitive) ~args loc : t =
   | Pint_as_pointer 
   | Pidentity ->  
     begin match args with [x] -> x | _ -> assert false end
+  | Pccall _ -> assert false      
   | Prevapply -> assert false     
   | Pdirapply -> assert false 
   | Ploc loc -> assert false (* already compiled away here*)    
@@ -66448,38 +66449,6 @@ let lam_prim ~primitive:( p : Lambda.primitive) ~args loc : t =
     -> prim ~primitive:(Pduprecord(repr,i)) ~args loc
   | Plazyforce -> prim ~primitive:Plazyforce ~args loc
 
-  | Pccall a -> 
-    let prim_name = a.prim_name in    
-    begin match Ast_ffi_types.from_string a.prim_native_name with 
-      | Ffi_normal -> 
-        if Pervasives.not @@ Ext_string.starts_with prim_name "js_" then 
-          prim ~primitive:(Pccall a ) ~args loc else 
-        if prim_name =  Literals.js_debugger then 
-          prim ~primitive:Pdebugger ~args loc else 
-        if prim_name =  Literals.js_fn_run || prim_name = Literals.js_method_run then
-          prim ~primitive:(Pjs_fn_run (int_of_string a.prim_native_name)) ~args loc else 
-        if prim_name = Literals.js_fn_mk then 
-          prim ~primitive:(Pjs_fn_make (int_of_string a.prim_native_name)) ~args loc else                
-        if prim_name = Literals.js_fn_method then 
-          prim ~primitive:(Pjs_fn_method (int_of_string a.prim_native_name)) ~args loc else
-        if prim_name = Literals.js_fn_runmethod then 
-          prim ~primitive:(Pjs_fn_runmethod (int_of_string a.prim_native_name)) ~args loc 
-        else
-          prim ~primitive:(Pccall a) ~args loc
-      | Ffi_obj_create labels -> 
-        prim ~primitive:(Pjs_object_create labels) ~args loc 
-      | Ffi_bs(arg_types, result_type, ffi) ->         
-
-        if no_auto_uncurried_arg_types arg_types then   
-          result_wrap loc result_type @@ prim ~primitive:(Pjs_call(prim_name, arg_types, ffi)) 
-            ~args loc 
-        else 
-          let n_arg_types, n_args = 
-            transform_uncurried_arg_type loc  arg_types args in 
-          result_wrap loc result_type @@
-          prim ~primitive:(Pjs_call (prim_name, n_arg_types, ffi))
-            ~args:n_args loc 
-    end
 
   | Praise _ ->
     if Js_config.get_no_any_assert () then 
@@ -66860,23 +66829,23 @@ let convert exports lam : _ * _  =
     | Lprim(Prevapply, [x ; f ],  outer_loc) 
     | Lprim(Pdirapply, [f ; x],  outer_loc) -> 
       begin match f with 
-               (* [x|>f] 
-          TODO: [airty = 0] when arity =0, it can not be escaped user can only
-          write  [f x ] instead of [x |> f ]
-         *)
+        (* [x|>f] 
+           TODO: [airty = 0] when arity =0, it can not be escaped user can only
+           write  [f x ] instead of [x |> f ]
+        *)
         | Lfunction(kind, [param],Lprim(external_fn,[Lvar inner_arg],inner_loc))
-           when Ident.same param inner_arg 
-            -> 
-           aux  (Lprim(external_fn,  [x], outer_loc))
+          when Ident.same param inner_arg 
+          -> 
+          aux  (Lprim(external_fn,  [x], outer_loc))
 
         |  Lapply(Lfunction(kind, params,Lprim(external_fn,inner_args,inner_loc)), args, outer_loc ) (* x |> f a *) 
-       
-           when Ext_list.for_all2_no_exn (fun x y -> match y with Lambda.Lvar y when Ident.same x y  -> true | _ -> false ) params inner_args
-           &&            
-          Ext_list.length_larger_than_n 1 inner_args args
-        -> 
-      
-         aux (Lprim(external_fn, args @ [x], outer_loc))
+
+          when Ext_list.for_all2_no_exn (fun x y -> match y with Lambda.Lvar y when Ident.same x y  -> true | _ -> false ) params inner_args
+               &&            
+               Ext_list.length_larger_than_n 1 inner_args args
+          -> 
+
+          aux (Lprim(external_fn, args @ [x], outer_loc))
         | _ -> 
           let x  = aux x in 
           let f =  aux f in 
@@ -66927,7 +66896,7 @@ let convert exports lam : _ * _  =
           prim ~primitive:Pnull_to_opt ~args:[aux arg] loc 
         | _ -> assert false 
       end  
-    | Lprim (Pccall {prim_name = "js_is_nil"}, args, loc) -> 
+    | Lprim (Pccall {prim_name = "js_is_nil" }, args, loc) -> 
       begin match args with 
         | [arg] -> prim ~primitive:Pis_null ~args:[aux arg] loc 
         | _ -> assert false 
@@ -66958,23 +66927,55 @@ let convert exports lam : _ * _  =
         | [e] -> prim ~primitive:Pjs_typeof ~args:[aux e] loc 
         | _ -> assert false
       end 
+    | Lprim(Pccall a, args, loc)  -> 
+      let args = List.map aux args in 
+      let prim_name = a.prim_name in    
+      begin match Ast_ffi_types.from_string a.prim_native_name with 
+        | Ffi_normal -> 
+          if Pervasives.not @@ Ext_string.starts_with prim_name "js_" then 
+            prim ~primitive:(Pccall a ) ~args loc else 
+          if prim_name =  Literals.js_debugger then 
+            prim ~primitive:Pdebugger ~args loc else 
+          if prim_name =  Literals.js_fn_run || prim_name = Literals.js_method_run then
+            prim ~primitive:(Pjs_fn_run (int_of_string a.prim_native_name)) ~args loc else 
+          if prim_name = Literals.js_fn_mk then 
+            prim ~primitive:(Pjs_fn_make (int_of_string a.prim_native_name)) ~args loc else                
+          if prim_name = Literals.js_fn_method then 
+            prim ~primitive:(Pjs_fn_method (int_of_string a.prim_native_name)) ~args loc else
+          if prim_name = Literals.js_fn_runmethod then 
+            prim ~primitive:(Pjs_fn_runmethod (int_of_string a.prim_native_name)) ~args loc 
+          else
+            prim ~primitive:(Pccall a) ~args loc
+        | Ffi_obj_create labels -> 
+          prim ~primitive:(Pjs_object_create labels) ~args loc 
+        | Ffi_bs(arg_types, result_type, ffi) ->         
+
+          if no_auto_uncurried_arg_types arg_types then   
+            result_wrap loc result_type @@ prim ~primitive:(Pjs_call(prim_name, arg_types, ffi)) 
+              ~args loc 
+          else 
+            let n_arg_types, n_args = 
+              transform_uncurried_arg_type loc  arg_types args in 
+            result_wrap loc result_type @@
+            prim ~primitive:(Pjs_call (prim_name, n_arg_types, ffi))
+              ~args:n_args loc 
+      end
 
+    (* TODO: pick a invalid external name to avod conflict *)  
+    | Lprim (Pgetglobal id, args, loc) ->   
+      let args = List.map aux args in 
+      if Ident.is_predef_exn id then 
+        Lprim {primitive = Pglobal_exception id; args ; loc}
+      else 
+        begin 
+          may_depend may_depends (Lam_module_ident.of_ml id);
+          assert (args = []);
+          Lglobal_module id 
+        end  
     | Lprim (primitive,args, loc) 
       -> 
-      let args = (List.map aux args) in
-      begin match primitive with 
-        | Pgetglobal id -> 
-          if Ident.is_predef_exn id then 
-            Lprim {primitive = Pglobal_exception id; args ; loc}
-          else 
-            begin 
-              may_depend may_depends (Lam_module_ident.of_ml id);
-              assert (args = []);
-              Lglobal_module id 
-            end  
-        | _ ->       
-          lam_prim ~primitive ~args loc 
-      end
+      let args = List.map aux args in
+      lam_prim ~primitive ~args loc 
     | Lswitch (e,s) -> 
       Lswitch (aux e, aux_switch s)
     | Lstringswitch (e, cases, default,_) -> 
@@ -67017,8 +67018,8 @@ let convert exports lam : _ * _  =
           Lsend(kind, aux a,  b, List.map aux ls, loc )
       end
     | Levent (e, event) ->
-       (* disabled by upstream*)
-       assert false
+      (* disabled by upstream*)
+      assert false
     | Lifused (id, e) -> 
       Lifused(id, aux e) (* TODO: remove it ASAP *)
   and aux_switch (s : Lambda.lambda_switch) : switch = 
@@ -91986,8 +91987,19 @@ let translate  loc
       | _ -> assert false 
       end    
   | Lam.Pnull_undefined_to_opt -> 
-    E.runtime_call Js_config.js_primitive
-    "js_from_nullable_def" args 
+    (*begin match args with 
+    | [e] -> 
+      begin match e.expression_desc with 
+      | Var _ -> 
+        E.econd (E.or_ (E.is_undef e) (E.is_nil e)) 
+          Js_of_lam_option.none 
+          (Js_of_lam_option.some e)
+      | _ ->*)
+       E.runtime_call Js_config.js_primitive        
+      "js_from_nullable_def" args 
+      (*end*)
+    (* | _ -> assert false  *)
+    (* end *)
   | Pis_null -> 
     begin match args with 
     | [e] -> E.is_nil e 
@@ -103402,15 +103414,14 @@ let rec unsafe_mapper : Ast_mapper.mapper =
              payload)
           ->
           let strip s =
-            let len = String.length s in            
-            if s.[len - 1] = '_' then
-              String.sub s 0 (len - 1)
-            else s in                  
+            match s with 
+            | "_module" -> "module" 
+            | x -> x  in 
           begin match Ast_payload.as_ident payload with
             | Some {txt = Lident
-                        ("__filename"
+                        ( "__filename"
                         | "__dirname"
-                        | "module_"
+                        | "_module"
                         | "require" as name); loc}
               ->
               let exp =
@@ -103419,7 +103430,7 @@ let rec unsafe_mapper : Ast_mapper.mapper =
                      (strip name) ) in
               let typ =
                 Ast_comb.to_undefined_type loc @@                 
-                if name = "module_" then
+                if name = "_module" then
                   Typ.constr ~loc
                     { txt = Ldot (Lident "Node", "node_module") ;
                       loc} []   
diff --git a/jscomp/build.sh b/jscomp/build.sh
index 418cb1c74a..86355a43dd 100755
--- a/jscomp/build.sh
+++ b/jscomp/build.sh
@@ -44,4 +44,11 @@ echo "Snapshot && update deps" >> ./build.compile
 
 make -C test depend 2>>../build.compile
 make -j7 depend snapshotml 2>> ./build.compile
+
+echo "Updating dependencies in runtime"
+cd runtime; make depend; cd ..
+
+echo "Updating dependencies in others"
+cd others; make depend; cd ..
+
 echo "Done" >> ./build.compile
diff --git a/jscomp/core/lam.ml b/jscomp/core/lam.ml
index 8a0ad0dd2e..680a79a384 100644
--- a/jscomp/core/lam.ml
+++ b/jscomp/core/lam.ml
@@ -1034,16 +1034,16 @@ let prim ~primitive:(prim : primitive) ~args:(ll : t list) loc  : t =
         Lift.int (int_of_float (float_of_string a))
       (* | Pnegfloat -> Lift.float (-. a) *)
       (* | Pabsfloat -> Lift.float (abs_float a) *)
-      | Pstringlength, ( (Const_string (a)) ) 
+      | Pstringlength, Const_string a
         -> 
         Lift.int (String.length a)
       (* | Pnegbint Pnativeint, ( (Const_nativeint i)) *)
       (*   ->   *)
       (*   Lift.nativeint (Nativeint.neg i) *)
-      | Pnegbint Pint32, ( (Const_int32 a))
+      | Pnegbint Pint32, Const_int32 a
         -> 
         Lift.int32 (Int32.neg a)
-      | Pnegbint Pint64, ( (Const_int64 a))
+      | Pnegbint Pint64, Const_int64 a
         -> 
         Lift.int64 (Int64.neg a)
       | Pnot , Const_pointer (a,_) 
@@ -1244,6 +1244,7 @@ let lam_prim ~primitive:( p : Lambda.primitive) ~args loc : t =
   | Pint_as_pointer 
   | Pidentity ->  
     begin match args with [x] -> x | _ -> assert false end
+  | Pccall _ -> assert false      
   | Prevapply -> assert false     
   | Pdirapply -> assert false 
   | Ploc loc -> assert false (* already compiled away here*)    
@@ -1279,38 +1280,6 @@ let lam_prim ~primitive:( p : Lambda.primitive) ~args loc : t =
     -> prim ~primitive:(Pduprecord(repr,i)) ~args loc
   | Plazyforce -> prim ~primitive:Plazyforce ~args loc
 
-  | Pccall a -> 
-    let prim_name = a.prim_name in    
-    begin match Ast_ffi_types.from_string a.prim_native_name with 
-      | Ffi_normal -> 
-        if Pervasives.not @@ Ext_string.starts_with prim_name "js_" then 
-          prim ~primitive:(Pccall a ) ~args loc else 
-        if prim_name =  Literals.js_debugger then 
-          prim ~primitive:Pdebugger ~args loc else 
-        if prim_name =  Literals.js_fn_run || prim_name = Literals.js_method_run then
-          prim ~primitive:(Pjs_fn_run (int_of_string a.prim_native_name)) ~args loc else 
-        if prim_name = Literals.js_fn_mk then 
-          prim ~primitive:(Pjs_fn_make (int_of_string a.prim_native_name)) ~args loc else                
-        if prim_name = Literals.js_fn_method then 
-          prim ~primitive:(Pjs_fn_method (int_of_string a.prim_native_name)) ~args loc else
-        if prim_name = Literals.js_fn_runmethod then 
-          prim ~primitive:(Pjs_fn_runmethod (int_of_string a.prim_native_name)) ~args loc 
-        else
-          prim ~primitive:(Pccall a) ~args loc
-      | Ffi_obj_create labels -> 
-        prim ~primitive:(Pjs_object_create labels) ~args loc 
-      | Ffi_bs(arg_types, result_type, ffi) ->         
-
-        if no_auto_uncurried_arg_types arg_types then   
-          result_wrap loc result_type @@ prim ~primitive:(Pjs_call(prim_name, arg_types, ffi)) 
-            ~args loc 
-        else 
-          let n_arg_types, n_args = 
-            transform_uncurried_arg_type loc  arg_types args in 
-          result_wrap loc result_type @@
-          prim ~primitive:(Pjs_call (prim_name, n_arg_types, ffi))
-            ~args:n_args loc 
-    end
 
   | Praise _ ->
     if Js_config.get_no_any_assert () then 
@@ -1691,23 +1660,23 @@ let convert exports lam : _ * _  =
     | Lprim(Prevapply, [x ; f ],  outer_loc) 
     | Lprim(Pdirapply, [f ; x],  outer_loc) -> 
       begin match f with 
-               (* [x|>f] 
-          TODO: [airty = 0] when arity =0, it can not be escaped user can only
-          write  [f x ] instead of [x |> f ]
-         *)
+        (* [x|>f] 
+           TODO: [airty = 0] when arity =0, it can not be escaped user can only
+           write  [f x ] instead of [x |> f ]
+        *)
         | Lfunction(kind, [param],Lprim(external_fn,[Lvar inner_arg],inner_loc))
-           when Ident.same param inner_arg 
-            -> 
-           aux  (Lprim(external_fn,  [x], outer_loc))
+          when Ident.same param inner_arg 
+          -> 
+          aux  (Lprim(external_fn,  [x], outer_loc))
 
         |  Lapply(Lfunction(kind, params,Lprim(external_fn,inner_args,inner_loc)), args, outer_loc ) (* x |> f a *) 
-       
-           when Ext_list.for_all2_no_exn (fun x y -> match y with Lambda.Lvar y when Ident.same x y  -> true | _ -> false ) params inner_args
-           &&            
-          Ext_list.length_larger_than_n 1 inner_args args
-        -> 
-      
-         aux (Lprim(external_fn, args @ [x], outer_loc))
+
+          when Ext_list.for_all2_no_exn (fun x y -> match y with Lambda.Lvar y when Ident.same x y  -> true | _ -> false ) params inner_args
+               &&            
+               Ext_list.length_larger_than_n 1 inner_args args
+          -> 
+
+          aux (Lprim(external_fn, args @ [x], outer_loc))
         | _ -> 
           let x  = aux x in 
           let f =  aux f in 
@@ -1758,7 +1727,7 @@ let convert exports lam : _ * _  =
           prim ~primitive:Pnull_to_opt ~args:[aux arg] loc 
         | _ -> assert false 
       end  
-    | Lprim (Pccall {prim_name = "js_is_nil"}, args, loc) -> 
+    | Lprim (Pccall {prim_name = "js_is_nil" }, args, loc) -> 
       begin match args with 
         | [arg] -> prim ~primitive:Pis_null ~args:[aux arg] loc 
         | _ -> assert false 
@@ -1789,23 +1758,55 @@ let convert exports lam : _ * _  =
         | [e] -> prim ~primitive:Pjs_typeof ~args:[aux e] loc 
         | _ -> assert false
       end 
+    | Lprim(Pccall a, args, loc)  -> 
+      let args = List.map aux args in 
+      let prim_name = a.prim_name in    
+      begin match Ast_ffi_types.from_string a.prim_native_name with 
+        | Ffi_normal -> 
+          if Pervasives.not @@ Ext_string.starts_with prim_name "js_" then 
+            prim ~primitive:(Pccall a ) ~args loc else 
+          if prim_name =  Literals.js_debugger then 
+            prim ~primitive:Pdebugger ~args loc else 
+          if prim_name =  Literals.js_fn_run || prim_name = Literals.js_method_run then
+            prim ~primitive:(Pjs_fn_run (int_of_string a.prim_native_name)) ~args loc else 
+          if prim_name = Literals.js_fn_mk then 
+            prim ~primitive:(Pjs_fn_make (int_of_string a.prim_native_name)) ~args loc else                
+          if prim_name = Literals.js_fn_method then 
+            prim ~primitive:(Pjs_fn_method (int_of_string a.prim_native_name)) ~args loc else
+          if prim_name = Literals.js_fn_runmethod then 
+            prim ~primitive:(Pjs_fn_runmethod (int_of_string a.prim_native_name)) ~args loc 
+          else
+            prim ~primitive:(Pccall a) ~args loc
+        | Ffi_obj_create labels -> 
+          prim ~primitive:(Pjs_object_create labels) ~args loc 
+        | Ffi_bs(arg_types, result_type, ffi) ->         
+
+          if no_auto_uncurried_arg_types arg_types then   
+            result_wrap loc result_type @@ prim ~primitive:(Pjs_call(prim_name, arg_types, ffi)) 
+              ~args loc 
+          else 
+            let n_arg_types, n_args = 
+              transform_uncurried_arg_type loc  arg_types args in 
+            result_wrap loc result_type @@
+            prim ~primitive:(Pjs_call (prim_name, n_arg_types, ffi))
+              ~args:n_args loc 
+      end
 
+    (* TODO: pick a invalid external name to avod conflict *)  
+    | Lprim (Pgetglobal id, args, loc) ->   
+      let args = List.map aux args in 
+      if Ident.is_predef_exn id then 
+        Lprim {primitive = Pglobal_exception id; args ; loc}
+      else 
+        begin 
+          may_depend may_depends (Lam_module_ident.of_ml id);
+          assert (args = []);
+          Lglobal_module id 
+        end  
     | Lprim (primitive,args, loc) 
       -> 
-      let args = (List.map aux args) in
-      begin match primitive with 
-        | Pgetglobal id -> 
-          if Ident.is_predef_exn id then 
-            Lprim {primitive = Pglobal_exception id; args ; loc}
-          else 
-            begin 
-              may_depend may_depends (Lam_module_ident.of_ml id);
-              assert (args = []);
-              Lglobal_module id 
-            end  
-        | _ ->       
-          lam_prim ~primitive ~args loc 
-      end
+      let args = List.map aux args in
+      lam_prim ~primitive ~args loc 
     | Lswitch (e,s) -> 
       Lswitch (aux e, aux_switch s)
     | Lstringswitch (e, cases, default,_) -> 
@@ -1848,8 +1849,8 @@ let convert exports lam : _ * _  =
           Lsend(kind, aux a,  b, List.map aux ls, loc )
       end
     | Levent (e, event) ->
-       (* disabled by upstream*)
-       assert false
+      (* disabled by upstream*)
+      assert false
     | Lifused (id, e) -> 
       Lifused(id, aux e) (* TODO: remove it ASAP *)
   and aux_switch (s : Lambda.lambda_switch) : switch = 
diff --git a/jscomp/core/lam_compile_primitive.ml b/jscomp/core/lam_compile_primitive.ml
index a78313a6ff..7e79ae956f 100644
--- a/jscomp/core/lam_compile_primitive.ml
+++ b/jscomp/core/lam_compile_primitive.ml
@@ -87,8 +87,19 @@ let translate  loc
       | _ -> assert false 
       end    
   | Lam.Pnull_undefined_to_opt -> 
-    E.runtime_call Js_config.js_primitive
-    "js_from_nullable_def" args 
+    (*begin match args with 
+    | [e] -> 
+      begin match e.expression_desc with 
+      | Var _ -> 
+        E.econd (E.or_ (E.is_undef e) (E.is_nil e)) 
+          Js_of_lam_option.none 
+          (Js_of_lam_option.some e)
+      | _ ->*)
+       E.runtime_call Js_config.js_primitive        
+      "js_from_nullable_def" args 
+      (*end*)
+    (* | _ -> assert false  *)
+    (* end *)
   | Pis_null -> 
     begin match args with 
     | [e] -> E.is_nil e 
diff --git a/jscomp/others/node_fs.ml b/jscomp/others/node_fs.ml
index 848783a18e..e0e0eba13b 100644
--- a/jscomp/others/node_fs.ml
+++ b/jscomp/others/node_fs.ml
@@ -124,5 +124,10 @@ external readFileSync :
   string = "readFileSync" 
 [@@bs.val] [@@bs.module "fs"]
 
+external readFileAsUtf8Sync : 
+  string -> (_[@bs.as "utf8"]) -> 
+  string = "readFileSync"
+[@@bs.val] [@@bs.module "fs"]  
+
 external existsSync : string -> bool = ""
 [@@bs.val] [@@bs.module "fs"]  
diff --git a/jscomp/runtime/.depend b/jscomp/runtime/.depend
index 81be433f1e..95355f3124 100644
--- a/jscomp/runtime/.depend
+++ b/jscomp/runtime/.depend
@@ -2,18 +2,18 @@ caml_array.cmj : caml_array.cmi
 caml_string.cmj : bs_string.cmj caml_string.cmi
 caml_bytes.cmj : caml_bytes.cmi
 caml_obj.cmj : js.cmj caml_array.cmj bs_obj.cmj caml_obj.cmi
-caml_int64.cmj : typed_array.cmj js_float.cmj js.cmj caml_utils.cmj \
-    caml_int32.cmj bs_string.cmj caml_int64.cmi
+caml_int64.cmj : typed_array.cmj js_float.cmj caml_utils.cmj caml_int32.cmj \
+    bs_string.cmj caml_int64.cmi
 caml_exceptions.cmj : caml_builtin_exceptions.cmj caml_exceptions.cmi
 caml_utils.cmj : caml_utils.cmi
 caml_sys.cmj : js_float.cmj caml_sys.cmi
 caml_io.cmj : js_undefined.cmj js.cmj bs_string.cmj
-caml_float.cmj : typed_array.cmj js_float.cmj js.cmj caml_float.cmi
+caml_float.cmj : typed_array.cmj js_float.cmj caml_float.cmi
 caml_lexer.cmj : caml_lexer.cmi
 caml_parser.cmj : caml_parser.cmi
 caml_primitive.cmj : caml_primitive.cmi
 caml_format.cmj : js_nativeint.cmj js_int64.cmj js_int.cmj js_float.cmj \
-    js.cmj caml_utils.cmj bs_string.cmj caml_format.cmi
+    caml_utils.cmj bs_string.cmj caml_format.cmi
 caml_md5.cmj : bs_string.cmj caml_md5.cmi
 caml_queue.cmj : caml_queue.cmi
 caml_hash.cmj : js_undefined.cmj js.cmj caml_queue.cmj bs_string.cmj \
@@ -22,14 +22,15 @@ caml_weak.cmj : js_undefined.cmj caml_array.cmj caml_weak.cmi
 caml_backtrace.cmj : caml_backtrace.cmi
 caml_int32.cmj : caml_int32.cmi
 caml_gc.cmj : caml_gc.cmi
-typed_array.cmj :
+typed_array.cmj : js.cmj
 js_primitive.cmj : js_undefined.cmj js.cmj js_primitive.cmi
 caml_basic.cmj : js_undefined.cmj js.cmj caml_basic.cmi
 caml_oo.cmj : caml_array.cmj bs_obj.cmj caml_oo.cmi
-curry.cmj : caml_oo.cmj caml_array.cmj
+curry.cmj : caml_array.cmj
+caml_oo_curry.cmj : curry.cmj caml_oo.cmj
 caml_module.cmj :
 bs_string.cmj :
-js_float.cmj : js.cmj
+js_float.cmj :
 bs_obj.cmj : js.cmj
 js_nativeint.cmj :
 js_int.cmj :
diff --git a/jscomp/runtime/Makefile b/jscomp/runtime/Makefile
index c7d431c175..98e805f407 100644
--- a/jscomp/runtime/Makefile
+++ b/jscomp/runtime/Makefile
@@ -17,6 +17,7 @@ caml_oo.cmj : caml_array.cmj
 js_unsafe.cmj:js_unsafe.cmi js.cmj js.cmi
 js_unsafe.cmi js.cmj: js.cmi
 caml_format.cmj caml_io.cmj caml_oo_curry.cmj: curry.cmj
+caml_format.cmj: caml_int64.cmj caml_int32.cmj caml_utils.cmj caml_string.cmj
 caml_weak.cmj caml_module.cmj: caml_obj.cmj js_primitive.cmj
 caml_builtin_exceptions.cmj: caml_builtin_exceptions.cmi js_unsafe.cmi
 block.cmj: block.cmi
diff --git a/jscomp/syntax/ppx_entry.ml b/jscomp/syntax/ppx_entry.ml
index fa17460837..9db810cfbf 100644
--- a/jscomp/syntax/ppx_entry.ml
+++ b/jscomp/syntax/ppx_entry.ml
@@ -274,15 +274,14 @@ let rec unsafe_mapper : Ast_mapper.mapper =
              payload)
           ->
           let strip s =
-            let len = String.length s in            
-            if s.[len - 1] = '_' then
-              String.sub s 0 (len - 1)
-            else s in                  
+            match s with 
+            | "_module" -> "module" 
+            | x -> x  in 
           begin match Ast_payload.as_ident payload with
             | Some {txt = Lident
-                        ("__filename"
+                        ( "__filename"
                         | "__dirname"
-                        | "module_"
+                        | "_module"
                         | "require" as name); loc}
               ->
               let exp =
@@ -291,7 +290,7 @@ let rec unsafe_mapper : Ast_mapper.mapper =
                      (strip name) ) in
               let typ =
                 Ast_comb.to_undefined_type loc @@                 
-                if name = "module_" then
+                if name = "_module" then
                   Typ.constr ~loc
                     { txt = Ldot (Lident "Node", "node_module") ;
                       loc} []   
diff --git a/jscomp/test/.depend b/jscomp/test/.depend
index 7c083b4d2c..2420213ed4 100644
--- a/jscomp/test/.depend
+++ b/jscomp/test/.depend
@@ -522,6 +522,7 @@ typed_array_test.cmj : ../runtime/typed_array.cmj mt.cmj ../runtime/js.cmj \
     ../stdlib/int32.cmj ../stdlib/array.cmj
 typeof_test.cmj : mt.cmj ../runtime/js.cmj
 uncurry_glob_test.cmj : ../runtime/caml_utils.cmj
+undef_regression2_test.cmj : ../runtime/js.cmj
 undef_regression_test.cmj : ../runtime/js.cmj ../runtime/bs_obj.cmj
 unicode_type_error.cmj :
 unitest_string.cmj :
diff --git a/jscomp/test/fs_test.ml b/jscomp/test/fs_test.ml
index d2679a0c3c..1ada1ee6df 100644
--- a/jscomp/test/fs_test.ml
+++ b/jscomp/test/fs_test.ml
@@ -39,7 +39,7 @@ let () =
   let _content = readFileSync current_file `utf8 in
   let _file_list = Fs.readdirSync current_dir_name in
   let pathobj =   Path.parse current_dir_name in
-  match Js.Undefined.to_opt [%bs.node module_] with
+  match Js.Undefined.to_opt [%bs.node _module] with
   | Some module_ ->   
     Js.log (module_##id, module_##paths) ;   
     eq __LOC__ (pathobj##name, "test" )
diff --git a/jscomp/test/test_require.ml b/jscomp/test/test_require.ml
index 47bcf8b0b1..3f9137904e 100644
--- a/jscomp/test/test_require.ml
+++ b/jscomp/test/test_require.ml
@@ -5,7 +5,7 @@ let () =
   | None ->   ()
   | Some u ->               
     Js.log @@ u#@resolve "./test_require.js";
-    if u##main == [%bs.node module_] && u##main != Js.Undefined.empty then
+    if u##main == [%bs.node _module] && u##main != Js.Undefined.empty then
       Js.log "is main"
     else
       Js.log "not main"
diff --git a/jscomp/test/undef_regression2_test.ml b/jscomp/test/undef_regression2_test.ml
new file mode 100644
index 0000000000..a1fe5a6833
--- /dev/null
+++ b/jscomp/test/undef_regression2_test.ml
@@ -0,0 +1,9 @@
+
+
+
+
+
+let a = 
+  match Js.Undefined.to_opt [%raw {|___undefined_value|}] with 
+  | None -> 1 
+  | Some _ -> 2 
\ No newline at end of file
diff --git a/site/docsource/Release.1.5.1.adoc b/site/docsource/Release.1.5.1.adoc
new file mode 100644
index 0000000000..a0b1225c9d
--- /dev/null
+++ b/site/docsource/Release.1.5.1.adoc
@@ -0,0 +1,6 @@
+
+
+
+# Minor breaking changes
+
+changes NodeJS special variables from `module_` to `_module` to make it more consistent
\ No newline at end of file