diff --git a/doc/guard.nvim.txt b/doc/guard.nvim.txt
index b4a0035..b55163d 100644
--- a/doc/guard.nvim.txt
+++ b/doc/guard.nvim.txt
@@ -1,4 +1,4 @@
-*guard.nvim.txt*         For NVIM v0.8.0         Last change: 2025 December 15
+*guard.nvim.txt*         For NVIM v0.8.0         Last change: 2025 December 16
 
 ==============================================================================
 Table of Contents                               *guard.nvim-table-of-contents*
diff --git a/lua/guard/lsp.lua b/lua/guard/lsp.lua
index 8575cfc..22a2e53 100644
--- a/lua/guard/lsp.lua
+++ b/lua/guard/lsp.lua
@@ -19,30 +19,35 @@ function M.format(buf, range, acc)
   api.nvim_buf_set_lines(scratch, 0, -1, false, vim.split(acc, '\r?\n'))
   local line_offset = range and range.start[1] - 1 or 0
 
-  return async.await(1, function(callback)
-    ---@diagnostic disable-next-line: duplicate-set-field
-    vim.lsp.util.apply_text_edits = function(text_edits, _, offset_encoding)
-      -- the target buffer must be buf, we apply it to our scratch buffer
-      n_edits = n_edits - 1
-      vim.tbl_map(function(edit)
-        edit.range.start.line = edit.range.start.line - line_offset
-        edit.range['end'].line = edit.range['end'].line - line_offset
-      end, text_edits)
-      apply(text_edits, scratch, offset_encoding)
-      if n_edits == 0 then
-        vim.lsp.util.apply_text_edits = apply
-        local lines = api.nvim_buf_get_lines(scratch, 0, -1, false)
-        api.nvim_command('silent! bwipe! ' .. scratch)
-        callback(table.concat(lines, '\n'))
+  for _, c in pairs(clients) do
+    acc = async.await(1, function(callback)
+      ---@diagnostic disable-next-line: duplicate-set-field
+      vim.lsp.util.apply_text_edits = function(text_edits, _, offset_encoding)
+        -- the target buffer must be buf, we apply it to our scratch buffer
+        n_edits = n_edits - 1
+        vim.tbl_map(function(edit)
+          edit.range.start.line = edit.range.start.line - line_offset
+          edit.range['end'].line = edit.range['end'].line - line_offset
+        end, text_edits)
+        apply(text_edits, scratch, offset_encoding)
+        if n_edits == 0 then
+          vim.lsp.util.apply_text_edits = apply
+          local lines = api.nvim_buf_get_lines(scratch, 0, -1, false)
+          api.nvim_command('silent! bwipe! ' .. scratch)
+          callback(table.concat(lines, '\n'))
+        end
       end
-    end
 
-    vim.lsp.buf.format({
-      bufnr = buf,
-      range = range,
-      async = true,
-    })
-  end)
+      vim.lsp.buf.format({
+        bufnr = buf,
+        range = range,
+        async = true,
+        id = c.id,
+      })
+    end)
+  end
+
+  return acc
 end
 
 return M
diff --git a/spec/lsp_spec.lua b/spec/lsp_spec.lua
index ba213d6..cf7894d 100644
--- a/spec/lsp_spec.lua
+++ b/spec/lsp_spec.lua
@@ -1,61 +1,68 @@
--- ---@diagnostic disable: undefined-field, undefined-global
--- require('plugin.guard')
--- local api = vim.api
--- local same = assert.are.same
--- local ft = require('guard.filetype')
--- local gapi = require('guard.api')
---
--- describe('format module', function()
---   local bufnr
---   local ill_c = {
---     'int main(     void ) {return 0;}',
---   }
---
---   before_each(function()
---     for k, _ in pairs(ft) do
---       ft[k] = nil
---     end
---     vim.g.guard_config = {
---       lsp_as_default_formatter = true,
---     }
---
---     vim.lsp.config('clangd', {
---       cmd = { 'clangd' },
---       filetypes = { 'c' },
---       capabilities = {
---         textDocument = {
---           formatting = {
---             dynamicRegistration = true,
---           },
---         },
---       },
---     })
---     vim.lsp.enable('clangd')
---
---     bufnr = api.nvim_create_buf(true, false)
---
---     vim.bo[bufnr].filetype = 'c'
---     api.nvim_set_current_buf(bufnr)
---     vim.cmd('silent! write! /tmp/lsp_spec_test.c')
---   end)
---
---   after_each(function()
---     vim.lsp.enable('clangd', false)
---   end)
---
---   local function getlines()
---     return api.nvim_buf_get_lines(bufnr, 0, -1, false)
---   end
---
---   local function setlines(lines)
---     api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
---   end
---
---   it('lsp default formatter works', function()
---     vim.wait(500)
---     setlines(ill_c)
---     gapi.fmt(bufnr)
---     vim.wait(500)
---     same({ 'int main(void) { return 0; }' }, getlines())
---   end)
--- end)
+---@diagnostic disable: undefined-field, undefined-global
+require('plugin.guard')
+local api = vim.api
+local same = assert.are.same
+local ft = require('guard.filetype')
+local gapi = require('guard.api')
+
+describe('format module', function()
+  local bufnr
+  local ill_c = {
+    'int main(     void ) {return 0;}',
+  }
+
+  before_each(function()
+    for k, _ in pairs(ft) do
+      ft[k] = nil
+    end
+    vim.g.guard_config = {
+      lsp_as_default_formatter = true,
+    }
+
+    vim.lsp.config('clangd', {
+      cmd = { 'clangd' },
+      filetypes = { 'c' },
+      capabilities = {
+        textDocument = {
+          formatting = {
+            dynamicRegistration = true,
+          },
+        },
+      },
+    })
+    vim.lsp.enable('clangd')
+
+    bufnr = api.nvim_create_buf(true, false)
+
+    vim.bo[bufnr].filetype = 'c'
+    api.nvim_set_current_buf(bufnr)
+    vim.cmd('silent! write! /tmp/lsp_spec_test.c')
+  end)
+
+  after_each(function()
+    vim.lsp.enable('clangd', false)
+  end)
+
+  local function getlines()
+    return api.nvim_buf_get_lines(bufnr, 0, -1, false)
+  end
+
+  local function setlines(lines)
+    api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
+  end
+
+  it('lsp default formatter works', function()
+    setlines(ill_c)
+    vim.api.nvim_create_autocmd('LspAttach', {
+      callback = function(args)
+        same(args.buf, bufnr)
+        same(args.file, '/tmp/lsp_spec_test.c')
+        same(args.match, '/tmp/lsp_spec_test.c')
+        gapi.fmt(bufnr)
+        vim.wait(500)
+        same({ 'int main(void) { return 0; }' }, getlines())
+      end,
+    })
+    vim.wait(1500)
+  end)
+end)