diff --git a/lua/gopher/_utils/init.lua b/lua/gopher/_utils/init.lua
index 96a9134..a6002e0 100644
--- a/lua/gopher/_utils/init.lua
+++ b/lua/gopher/_utils/init.lua
@@ -23,4 +23,10 @@ function utils.notify(msg, lvl)
   log.debug(msg)
 end
 
+---@param path string
+---@return string
+function utils.readfile_joined(path)
+  return vim.fn.join(vim.fn.readfile(path), "\n")
+end
+
 return utils
diff --git a/lua/gopher/iferr.lua b/lua/gopher/iferr.lua
index a3a193e..775edc7 100644
--- a/lua/gopher/iferr.lua
+++ b/lua/gopher/iferr.lua
@@ -4,27 +4,33 @@
 ---@usage Execute `:GoIfErr` near any `err` variable to insert the check
 
 local c = require "gopher.config"
+local u = require "gopher._utils"
+local r = require "gopher._utils.runner"
 local log = require "gopher._utils.log"
 local iferr = {}
 
--- That's Lua implementation: github.com/koron/iferr
+-- That's Lua implementation: https://github.com/koron/iferr
 function iferr.iferr()
-  local boff = vim.fn.wordcount().cursor_bytes
+  local curb = vim.fn.wordcount().cursor_bytes
   local pos = vim.fn.getcurpos()[2]
+  local fpath = vim.fn.expand "%"
 
-  local data = vim.fn.systemlist((c.commands.iferr .. " -pos " .. boff), vim.fn.bufnr "%")
-  if vim.v.shell_error ~= 0 then
-    if string.find(data[1], "no functions at") then
-      vim.print "no function found"
-      log.warn("iferr: no function at " .. boff)
+  local rs = r.sync({ c.commands.iferr, "-pos", curb }, {
+    stdin = u.readfile_joined(fpath),
+  })
+
+  if rs.code ~= 0 then
+    if string.find(rs.stderr, "no functions at") then
+      u.notify("iferr: no function at " .. curb, vim.log.levels.ERROR)
+      log.warn("iferr: no function at " .. curb)
       return
     end
 
-    log.error("failed. output: " .. vim.inspect(data))
-    error("iferr failed: " .. vim.inspect(data))
+    log.error("ferr: failed. output: " .. vim.inspect(rs.stderr))
+    error("iferr failed: " .. rs.stderr)
   end
 
-  vim.fn.append(pos, data)
+  vim.fn.append(pos, vim.fn.split(rs.stdout, "\n"))
   vim.cmd [[silent normal! j=2j]]
   vim.fn.setpos(".", pos)
 end