diff --git a/lua/navigator/codelens.lua b/lua/navigator/codelens.lua
index 41a79c9..40a0b96 100644
--- a/lua/navigator/codelens.lua
+++ b/lua/navigator/codelens.lua
@@ -4,8 +4,6 @@
 local codelens = require('vim.lsp.codelens')
 
 local log = require('navigator.util').log
-local mk_handler = require('navigator.util').mk_handler
-local nvim_0_6_1 = require('navigator.util').nvim_0_6_1
 local trace = require('navigator.util').trace
 
 local lsphelper = require('navigator.lspwrapper')
@@ -49,7 +47,7 @@ local function _update_sign(line)
   end
 end
 
-local codelens_hdlr = mk_handler(function(err, result, ctx, cfg)
+local codelens_hdlr = function(err, result, ctx, cfg)
   trace(ctx, result)
   M.codelens_ctx = ctx
   if err or result == nil then
@@ -62,7 +60,7 @@ local codelens_hdlr = mk_handler(function(err, result, ctx, cfg)
   for _, v in pairs(result) do
     _update_sign(v.range.start.line)
   end
-end)
+end
 
 function M.setup()
   vim.cmd('highlight! link LspCodeLens LspDiagnosticsHint')
@@ -75,18 +73,13 @@ function M.setup()
   vim.cmd("autocmd BufEnter,CursorHold,InsertLeave <buffer> lua require('navigator.codelens').refresh()")
   vim.cmd('augroup end')
   local on_codelens = vim.lsp.handlers['textDocument/codeLens']
-  vim.lsp.handlers['textDocument/codeLens'] = mk_handler(function(err, result, ctx, cfg)
+  vim.lsp.handlers['textDocument/codeLens'] = function(err, result, ctx, cfg)
     -- trace(err, result, ctx.client_id, ctx.bufnr, cfg or {})
     cfg = cfg or {}
     ctx = ctx or { bufnr = vim.api.nvim_get_current_buf() }
-    if nvim_0_6_1() then
-      on_codelens(err, result, ctx, cfg)
-      codelens_hdlr(err, result, ctx, cfg)
-    else
-      on_codelens(err, ctx.method, result, ctx.client_id, ctx.bufnr)
-      codelens_hdlr(err, nil, result, ctx.client_id or 0, ctx.bufnr or 0)
-    end
-  end)
+    on_codelens(err, result, ctx, cfg)
+    codelens_hdlr(err, result, ctx, cfg)
+  end
 end
 
 M.lsp_clients = {}
diff --git a/lua/navigator/definition.lua b/lua/navigator/definition.lua
index d02dc0c..c14c7f5 100644
--- a/lua/navigator/definition.lua
+++ b/lua/navigator/definition.lua
@@ -5,7 +5,7 @@ local gui = require('navigator.gui')
 local log = util.log
 local TextView = require('guihua.textview')
 -- callback for lsp definition, implementation and declaration handler
-local definition_hdlr = util.mk_handler(function(err, locations, ctx, _)
+local definition_hdlr = function(err, locations, ctx, _)
   -- log(locations)
   if err ~= nil then
     vim.notify('Defination: ' .. tostring(err) .. vim.inspect(ctx), vim.lsp.log_levels.WARN)
@@ -31,7 +31,7 @@ local definition_hdlr = util.mk_handler(function(err, locations, ctx, _)
   else
     vim.lsp.util.jump_to_location(locations, oe)
   end
-end)
+end
 
 local function get_symbol()
   local currentWord = vim.fn.expand('<cword>')
diff --git a/lua/navigator/diagnostics.lua b/lua/navigator/diagnostics.lua
index 244c963..c3f75bc 100644
--- a/lua/navigator/diagnostics.lua
+++ b/lua/navigator/diagnostics.lua
@@ -9,7 +9,6 @@ local trace = require('guihua.log').trace
 -- trace = log
 local error = util.error
 local path_sep = require('navigator.util').path_sep()
-local mk_handler = require('navigator.util').mk_handler
 local path_cur = require('navigator.util').path_cur()
 local empty = util.empty
 
@@ -194,7 +193,7 @@ local update_err_marker_async = function()
   return debounce(400, error_marker)
 end
 
-local diag_hdlr = mk_handler(function(err, result, ctx, config)
+local diag_hdlr = function(err, result, ctx, config)
   require('navigator.lspclient.highlight').diagnositc_config_sign()
   config = config or diagnostic_cfg
   if err ~= nil then
@@ -305,7 +304,7 @@ local diag_hdlr = mk_handler(function(err, result, ctx, config)
     vim.api.nvim_buf_clear_namespace(0, _NG_VT_DIAG_NS, 0, -1)
     _NG_VT_DIAG_NS = nil
   end
-end)
+end
 
 local diag_hdlr_async = function()
   local debounce = require('navigator.debounce').debounce_trailing
diff --git a/lua/navigator/dochighlight.lua b/lua/navigator/dochighlight.lua
index 1b97f01..97b6ede 100644
--- a/lua/navigator/dochighlight.lua
+++ b/lua/navigator/dochighlight.lua
@@ -1,7 +1,6 @@
 local util = require('navigator.util')
 local log = util.log
 local trace = util.trace
-local mk_handler = util.mk_handler
 local api = vim.api
 local references = {}
 _NG_hi_list = {}
@@ -139,7 +138,7 @@ local function before(r1, r2)
   return false
 end
 
-local handle_document_highlight = mk_handler(function(_, result, ctx)
+local handle_document_highlight = function(_, result, ctx)
   trace(result, ctx)
   if not ctx.bufnr then
     log('ducment highlight error', result, ctx)
@@ -157,7 +156,7 @@ local handle_document_highlight = mk_handler(function(_, result, ctx)
   references[ctx.bufnr] = result
   local client_id = ctx.client_id
   vim.lsp.util.buf_highlight_references(ctx.bufnr, result, util.encoding(client_id))
-end)
+end
 -- modify from vim-illuminate
 local function goto_adjent_reference(opt)
   trace(opt)
@@ -227,7 +226,7 @@ local function documentHighlight()
     ]],
     false
   )
-  vim.lsp.handlers['textDocument/documentHighlight'] = mk_handler(function(err, result, ctx)
+  vim.lsp.handlers['textDocument/documentHighlight'] = function(err, result, ctx)
     local bufnr = ctx.bufnr or api.nvim_get_current_buf()
     if err then
       vim.notify(err, vim.lsp.log_levels.ERROR)
@@ -250,7 +249,7 @@ local function documentHighlight()
     end)
     references[bufnr] = result
     add_locs(bufnr, result)
-  end)
+  end
 end
 
 return {
diff --git a/lua/navigator/foldlsp.lua b/lua/navigator/foldlsp.lua
index 43f3f6b..6e70528 100644
--- a/lua/navigator/foldlsp.lua
+++ b/lua/navigator/foldlsp.lua
@@ -1,5 +1,4 @@
 local log = require('navigator.util').log
-local mk_handler = require('navigator.util').mk_handler
 
 local lsp = vim.lsp
 local api = vim.api
@@ -88,7 +87,7 @@ function M.debug_folds()
   end
 end
 
-M.fold_handler = mk_handler(function(err, result, ctx, config)
+M.fold_handler = function(err, result, ctx, config)
   -- params: err, method, result, client_id, bufnr
   -- XXX: handle err?
   if err or result == nil or #result == 0 then
@@ -112,7 +111,7 @@ M.fold_handler = mk_handler(function(err, result, ctx, config)
     api.nvim_win_set_option(current_window, 'foldmethod', 'expr')
     api.nvim_win_set_option(current_window, 'foldexpr', 'foldlsp#foldexpr()')
   end
-end)
+end
 
 function M.adjust_foldstart(line_no)
   return line_no + 1
diff --git a/lua/navigator/formatting.lua b/lua/navigator/formatting.lua
index ad9ce6c..18f4954 100644
--- a/lua/navigator/formatting.lua
+++ b/lua/navigator/formatting.lua
@@ -1,8 +1,7 @@
 -- https://github.com/wention/dotfiles/blob/master/.config/nvim/lua/config/lsp.lua
 -- https://github.com/lukas-reineke/dotfiles/blob/master/vim/lua/lsp/handlers.lua
-local mk_handler = require('navigator.util').mk_handler
 return {
-  format_hdl = mk_handler(function(err, result, ctx, cfg) -- FIXME: bufnr is nil
+  format_hdl = function(err, result, ctx, cfg) -- FIXME: bufnr is nil
     if err ~= nil or result == nil then
       return
     end
@@ -31,5 +30,5 @@ return {
         -- end
       end
     end, 100)
-  end),
+  end,
 }
diff --git a/lua/navigator/implementation.lua b/lua/navigator/implementation.lua
index 208641d..7c2e0f8 100644
--- a/lua/navigator/implementation.lua
+++ b/lua/navigator/implementation.lua
@@ -1,5 +1,4 @@
 local util = require('navigator.util')
-local mk_handler = util.mk_handler
 local lsphelper = require('navigator.lspwrapper')
 local gui = require('navigator.gui')
 local M = {}
diff --git a/lua/navigator/lspclient/clients.lua b/lua/navigator/lspclient/clients.lua
index 8f5d36b..2f0b769 100644
--- a/lua/navigator/lspclient/clients.lua
+++ b/lua/navigator/lspclient/clients.lua
@@ -432,8 +432,25 @@ local function load_cfg(ft, client, cfg, loaded)
   -- need to verify the lsp server is up
 end
 
+local function setup_fmt(client, enabled)
+  if not require('navigator.util').nvim_0_8() then
+    if enabled == false then
+      client.resolved_capabilities.document_formatting = enabled
+    else
+      client.resolved_capabilities.document_formatting = client.resolved_capabilities.document_formatting or enabled
+    end
+  end
+
+  if enabled == false then
+    client.server_capabilities.documentFormattingProvider = false
+  else
+    client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
+      or enabled
+  end
+end
+
 local function update_capabilities()
-  trace(ft, 'lsp startup')
+  trace(vim.o.ft, 'lsp startup')
   local loaded = {}
   local capabilities = vim.lsp.protocol.make_client_capabilities()
   capabilities.textDocument.completion.completionItem.snippetSupport = true
@@ -521,6 +538,7 @@ local function lsp_startup(ft, retry, user_lsp_opts)
     -- filetype disabled
     if not vim.tbl_contains(cfg.filetypes or {}, ft) then
       trace('ft', ft, 'disabled for', lspclient)
+
       goto continue
     end
 
@@ -539,15 +557,7 @@ local function lsp_startup(ft, retry, user_lsp_opts)
       -- log(lsp_opts[lspclient], cfg)
       cfg = vim.tbl_deep_extend('force', cfg, user_lsp_opts[lspclient])
       if config.combined_attach == nil then
-        cfg.on_attach = function(client, bufnr)
-          on_attach(client, bufnr)
-          if enable_fmt then
-            client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
-              or enable_fmt
-          else
-            client.server_capabilities.documentFormattingProvider = false
-          end
-        end
+        setup_fmt(client, enable_fmt)
       end
       if config.combined_attach == 'mine' then
         if config.on_attach == nil then
@@ -555,12 +565,8 @@ local function lsp_startup(ft, retry, user_lsp_opts)
         end
         cfg.on_attach = function(client, bufnr)
           config.on_attach(client, bufnr)
-          if enable_fmt then
-            client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
-              or enable_fmt
-          else
-            client.server_capabilities.documentFormattingProvider = false
-          end
+
+          setup_fmt(client, enable_fmt)
           require('navigator.lspclient.mapping').setup({
             client = client,
             bufnr = bufnr,
@@ -572,12 +578,7 @@ local function lsp_startup(ft, retry, user_lsp_opts)
         cfg.on_attach = function(client, bufnr)
           on_attach(client, bufnr)
           config.on_attach(client, bufnr)
-          if enable_fmt then
-            client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
-              or enable_fmt
-          else
-            client.server_capabilities.documentFormattingProvider = false
-          end
+          setup_fmt(client, enable_fmt)
           require('navigator.lspclient.mapping').setup({
             client = client,
             bufnr = bufnr,
@@ -587,12 +588,7 @@ local function lsp_startup(ft, retry, user_lsp_opts)
       end
       if config.combined_attach == 'both' then
         cfg.on_attach = function(client, bufnr)
-          if enable_fmt then
-            client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
-              or enable_fmt
-          else
-            client.server_capabilities.documentFormattingProvider = false
-          end
+          setup_fmt(client, enable_fmt)
 
           if config.on_attach and type(config.on_attach) == 'function' then
             config.on_attach(client, bufnr)
@@ -622,12 +618,7 @@ local function lsp_startup(ft, retry, user_lsp_opts)
       cfg.on_attach = function(client, bufnr)
         on_attach(client, bufnr)
 
-        if enable_fmt then
-          client.server_capabilities.documentFormattingProvider = client.server_capabilities.documentFormattingProvider
-            or enable_fmt
-        else
-          client.server_capabilities.documentFormattingProvider = false
-        end
+        setup_fmt(client, enable_fmt)
       end
     end
 
diff --git a/lua/navigator/lspwrapper.lua b/lua/navigator/lspwrapper.lua
index c1164b8..3439fc5 100644
--- a/lua/navigator/lspwrapper.lua
+++ b/lua/navigator/lspwrapper.lua
@@ -1,7 +1,6 @@
 local M = {}
 
 local util = require('navigator.util')
-local nvim_0_6_1 = util.nvim_0_6_1()
 
 local gutil = require('guihua.util')
 local lsp = require('vim.lsp')
@@ -146,11 +145,7 @@ function M.call_sync(method, params, opts, handler)
   opts = opts or {}
   local results_lsp, err = lsp.buf_request_sync(0, method, params, opts.timeout or vim.g.navtator_timeout or 1000)
 
-  if nvim_0_6_1 then
-    handler(err, extract_result(results_lsp), { method = method }, nil)
-  else
-    handler(err, method, extract_result(results_lsp), nil, nil)
-  end
+  handler(err, extract_result(results_lsp), { method = method }, nil)
 end
 
 function M.call_async(method, params, handler)
diff --git a/lua/navigator/reference.lua b/lua/navigator/reference.lua
index cfc3bdb..ae4ae7c 100644
--- a/lua/navigator/reference.lua
+++ b/lua/navigator/reference.lua
@@ -1,5 +1,4 @@
 local util = require('navigator.util')
-local mk_handler = util.mk_handler
 local log = util.log
 local lsphelper = require('navigator.lspwrapper')
 local gui = require('navigator.gui')
@@ -135,7 +134,7 @@ local ref_view = function(err, locations, ctx, cfg)
   return listview, items, width
 end
 
-local ref_hdlr = mk_handler(function(err, locations, ctx, cfg)
+local ref_hdlr = function(err, locations, ctx, cfg)
   _NgConfigValues.closer = nil
   trace(err, locations, ctx, cfg)
   M.async_hdlr = vim.loop.new_async(vim.schedule_wrap(function()
@@ -145,7 +144,7 @@ local ref_hdlr = mk_handler(function(err, locations, ctx, cfg)
     end
   end))
   M.async_hdlr:send()
-end)
+end
 
 local async_ref = function()
   local ref_params = vim.lsp.util.make_position_params()
diff --git a/lua/navigator/signature.lua b/lua/navigator/signature.lua
index 62afa6e..1d15ea9 100644
--- a/lua/navigator/signature.lua
+++ b/lua/navigator/signature.lua
@@ -1,6 +1,5 @@
 local gui = require "navigator.gui"
 local util = require "navigator.util"
-local mk_handler = util.mk_handler
 local log = util.log
 local partial = util.partial
 local lsphelper = require "navigator.lspwrapper"
@@ -47,7 +46,7 @@ local match_parameter = function(result)
   end
 end
 
-local signature_handler = mk_handler(function(err, result, ctx, config)
+local signature_handler = function(err, result, ctx, config)
   if config == nil then
     log("config nil")
   end
@@ -71,5 +70,5 @@ local signature_handler = mk_handler(function(err, result, ctx, config)
   local syntax = vim.lsp.util.try_trim_markdown_code_blocks(lines)
   config.focus_id = ctx.bufnr .. "lsp_signature"
   vim.lsp.util.open_floating_preview(lines, syntax, config)
-end)
+end
 return {signature_handler = signature_handler}
diff --git a/lua/navigator/symbols.lua b/lua/navigator/symbols.lua
index 939f348..055d30a 100644
--- a/lua/navigator/symbols.lua
+++ b/lua/navigator/symbols.lua
@@ -2,7 +2,6 @@ local gui = require('navigator.gui')
 local M = {}
 local log = require('navigator.util').log
 local trace = require('navigator.util').trace
-local mk_handler = require('navigator.util').mk_handler
 local lsphelper = require('navigator.lspwrapper')
 local locations_to_items = lsphelper.locations_to_items
 local clone = require('guihua.util').clone
@@ -43,7 +42,7 @@ function M.document_symbols(opts)
   end)
 end
 
-M.document_symbol_handler = mk_handler(function(err, result, ctx)
+M.document_symbol_handler = function(err, result, ctx)
   if err then
     vim.notify('failed to get document symbol' .. vim.inspect(ctx), vim.lsp.log_levels.WARN)
   end
@@ -101,9 +100,9 @@ M.document_symbol_handler = mk_handler(function(err, result, ctx)
 
   local ft = vim.api.nvim_buf_get_option(bufnr, 'ft')
   gui.new_list_view({ items = locations, prompt = true, rawdata = true, ft = ft, api = ' ' })
-end)
+end
 
-M.workspace_symbol_handler = mk_handler(function(err, result, ctx, cfg)
+M.workspace_symbol_handler = function(err, result, ctx, cfg)
   trace(err, result, ctx, cfg)
   if err then
     vim.notify('failed to get workspace symbol' .. vim.inspect(ctx), vim.lsp.log_levels.WARN)
@@ -123,6 +122,6 @@ M.workspace_symbol_handler = mk_handler(function(err, result, ctx, cfg)
 
   local ft = vim.api.nvim_buf_get_option(ctx.bufnr, 'ft')
   gui.new_list_view({ items = items, prompt = true, ft = ft, rowdata = true, api = ' ' })
-end)
+end
 
 return M
diff --git a/lua/navigator/util.lua b/lua/navigator/util.lua
index 1d6fc4d..87a5c06 100644
--- a/lua/navigator/util.lua
+++ b/lua/navigator/util.lua
@@ -5,6 +5,7 @@ local M = { log_path = vim.lsp.get_log_path() }
 -- local is_windows = uv.os_uname().version:match("Windows")
 local guihua = require('guihua.util')
 local nvim_0_6_1
+local nvim_0_8
 
 M.path_sep = function()
   local is_win = vim.loop.os_uname().sysname:find('Windows')
@@ -354,11 +355,20 @@ function M.nvim_0_6_1()
   return nvim_0_6_1
 end
 
+function M.nvim_0_8()
+  if nvim_0_8 ~= nil then
+    return nvim_0_8
+  end
+  nvim_0_8 = vim.fn.has('nvim-0.8') == 1
+  if nvim_0_8 == false then
+    M.warn('Please use navigator 0.4 version for neovim version < 0.8')
+  end
+  return nvim_0_8
+end
+
 function M.mk_handler(fn)
   return function(...)
-    if M.nvim_0_6_1() then
-      return fn(...)
-    end
+    return fn(...)
   end
 end
 
@@ -392,7 +402,7 @@ function M.encoding(client)
     return 'utf-8'
   end
   if type(oe) == 'table' then
-    oe = oe[1] or 'utf-8'
+    return oe[1]
   end
   return oe
 end