diff --git a/lua/copilot/client/init.lua b/lua/copilot/client/init.lua
index bff572a3..a7329f35 100644
--- a/lua/copilot/client/init.lua
+++ b/lua/copilot/client/init.lua
@@ -39,8 +39,12 @@ function M.buf_is_attached(bufnr)
 end
 
 ---@param force? boolean
-function M.buf_attach(force)
-  local bufnr = vim.api.nvim_get_current_buf()
+---@param bufnr? integer The buffer number of which will be attached. 0 or nil for current buffer
+function M.buf_attach(force, bufnr)
+  bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
 
   if lsp.initialization_failed() then
     logger.error("copilot-language-server failed to initialize")
@@ -53,7 +57,7 @@ function M.buf_attach(force)
     return
   end
 
-  if not (force or util.should_attach()) then
+  if not (force or util.should_attach(bufnr)) then
     logger.debug("not attaching to buffer based on force and should_attach criteria")
     return
   end
@@ -163,9 +167,11 @@ function M.setup()
 
   vim.api.nvim_create_autocmd("FileType", {
     group = M.augroup,
-    callback = vim.schedule_wrap(function()
-      M.buf_attach()
-    end),
+    callback = function(ev)
+      vim.schedule(function()
+        M.buf_attach(nil, ev.buf)
+      end)
+    end,
   })
 
   vim.schedule(M.ensure_client_started)
diff --git a/lua/copilot/command.lua b/lua/copilot/command.lua
index 0ac76a1f..7a09782c 100644
--- a/lua/copilot/command.lua
+++ b/lua/copilot/command.lua
@@ -29,13 +29,13 @@ function M.version()
   end)()
 end
 
----@param opts? { force?: boolean }
+---@param opts? { force?: boolean, bufnr?: integer}
 function M.attach(opts)
   logger.trace("attaching to buffer")
   opts = opts or {}
 
   if not opts.force then
-    local should_attach, no_attach_reason = u.should_attach()
+    local should_attach, no_attach_reason = u.should_attach(opts.bufnr)
 
     if not should_attach then
       logger.notify(no_attach_reason .. "\nto force attach, run ':Copilot! attach'")
@@ -45,7 +45,7 @@ function M.attach(opts)
     opts.force = true
   end
 
-  c.buf_attach(opts.force)
+  c.buf_attach(opts.force, opts.bufnr)
 end
 
 function M.detach()
diff --git a/lua/copilot/util.lua b/lua/copilot/util.lua
index 2efa1af8..04085d94 100644
--- a/lua/copilot/util.lua
+++ b/lua/copilot/util.lua
@@ -34,15 +34,23 @@ end
 
 ---@return boolean should_attach
 ---@return string? no_attach_reason
-function M.should_attach()
+function M.should_attach(bufnr)
+  bufnr = bufnr or vim.api.nvim_get_current_buf()
+  if bufnr == 0 then
+    bufnr = vim.api.nvim_get_current_buf()
+  end
+
+  if not vim.api.nvim_buf_is_valid(bufnr) then
+    return false, "Invalid buffer"
+  end
+
   local ft = config.filetypes
-  local ft_disabled, ft_disabled_reason = require("copilot.client.filetypes").is_ft_disabled(vim.bo.filetype, ft)
+  local ft_disabled, ft_disabled_reason = require("copilot.client.filetypes").is_ft_disabled(vim.bo[bufnr].filetype, ft)
 
   if ft_disabled then
     return not ft_disabled, ft_disabled_reason
   end
 
-  local bufnr = vim.api.nvim_get_current_buf()
   local bufname = vim.api.nvim_buf_get_name(bufnr)
   local conf_attach = config.should_attach(bufnr, bufname)