diff --git a/test/testutil.lua b/test/testutil.lua
index 62cf1b18ca..fb018a3e9e 100644
--- a/test/testutil.lua
+++ b/test/testutil.lua
@@ -5,17 +5,6 @@ local Paths = require('test.cmakeconfig.paths')
 
 luaassert:set_parameter('TableFormatLevel', 100)
 
-local quote_me = '[^.%w%+%-%@%_%/]' -- complement (needn't quote)
-
---- @param str string
---- @return string
-local function shell_quote(str)
-  if string.find(str, quote_me) or str == '' then
-    return '"' .. str:gsub('[$%%"\\]', '\\%0') .. '"'
-  end
-  return str
-end
-
 --- Functions executing in the context of the test runner (not the current nvim test session).
 --- @class test.testutil
 local M = {
@@ -66,19 +55,15 @@ function M.argss_to_cmd(...)
   for i = 1, select('#', ...) do
     local arg = select(i, ...)
     if type(arg) == 'string' then
-      cmd[#cmd + 1] = shell_quote(arg)
+      cmd[#cmd + 1] = arg
     else
       --- @cast arg string[]
       for _, subarg in ipairs(arg) do
-        cmd[#cmd + 1] = shell_quote(subarg)
+        cmd[#cmd + 1] = subarg
       end
     end
   end
-  return table.concat(cmd, ' ')
-end
-
-function M.popen_r(...)
-  return io.popen(M.argss_to_cmd(...), 'r')
+  return cmd
 end
 
 --- Calls fn() until it succeeds, up to `max` times or until `max_ms`
@@ -356,7 +341,7 @@ function M.check_logs()
           local status, f
           local out = io.stdout
           if os.getenv('SYMBOLIZER') then
-            status, f = pcall(M.popen_r, os.getenv('SYMBOLIZER'), '-l', file)
+            status, f = pcall(M.repeated_read_cmd, os.getenv('SYMBOLIZER'), '-l', file)
           end
           out:write(start_msg .. '\n')
           if status then
@@ -539,16 +524,37 @@ end
 
 --- @return string?
 function M.repeated_read_cmd(...)
-  for _ = 1, 10 do
-    local stream = M.popen_r(...)
-    local ret = stream:read('*a')
-    stream:close()
-    if ret then
-      return ret
+  local cmd = M.argss_to_cmd(...)
+  local data = {}
+  local got_code = nil
+  local stdout = assert(vim.uv.new_pipe(false))
+  local handle = assert(
+    vim.uv.spawn(
+      cmd[1],
+      { args = vim.list_slice(cmd, 2), stdio = { nil, stdout, 2 }, hide = true },
+      function(code, _signal)
+        got_code = code
+      end
+    )
+  )
+  stdout:read_start(function(err, chunk)
+    if err or chunk == nil then
+      stdout:read_stop()
+      stdout:close()
+    else
+      table.insert(data, chunk)
     end
+  end)
+
+  while not stdout:is_closing() or got_code == nil do
+    vim.uv.run('once')
   end
-  print('ERROR: Failed to execute ' .. M.argss_to_cmd(...) .. ': nil return after 10 attempts')
-  return nil
+
+  if got_code ~= 0 then
+    error('command ' .. vim.inspect(cmd) .. 'unexpectedly exited with status ' .. got_code)
+  end
+  handle:close()
+  return table.concat(data)
 end
 
 --- @generic T
diff --git a/test/unit/api/private_helpers_spec.lua b/test/unit/api/private_helpers_spec.lua
index bdfc83a031..4d9c2e5046 100644
--- a/test/unit/api/private_helpers_spec.lua
+++ b/test/unit/api/private_helpers_spec.lua
@@ -18,7 +18,7 @@ local type_key = api_t.type_key
 local obj2lua = api_t.obj2lua
 local func_type = api_t.func_type
 
-local api = cimport('./src/nvim/api/private/t.h', './src/nvim/api/private/converter.h')
+local api = cimport('./src/nvim/api/private/helpers.h', './src/nvim/api/private/converter.h')
 
 describe('vim_to_object', function()
   local vim_to_object = function(l)
diff --git a/test/unit/api/testutil.lua b/test/unit/api/testutil.lua
index bb387ae0e1..77c9d608cf 100644
--- a/test/unit/api/testutil.lua
+++ b/test/unit/api/testutil.lua
@@ -13,8 +13,11 @@ local int_type = t_eval.int_type
 local flt_type = t_eval.flt_type
 local type_key = t_eval.type_key
 
-local api =
-  cimport('./src/nvim/api/private/defs.h', './src/nvim/api/private/t.h', './src/nvim/memory.h')
+local api = cimport(
+  './src/nvim/api/private/defs.h',
+  './src/nvim/api/private/helpers.h',
+  './src/nvim/memory.h'
+)
 
 local obj2lua
 
diff --git a/test/unit/vterm_spec.lua b/test/unit/vterm_spec.lua
index c5293a21cb..aab895b7dc 100644
--- a/test/unit/vterm_spec.lua
+++ b/test/unit/vterm_spec.lua
@@ -94,7 +94,7 @@ local vterm = t.cimport(
   './src/nvim/vterm/screen.h',
   './src/nvim/vterm/state.h',
   './src/nvim/vterm/vterm.h',
-  './src/nvim/vterm/vterm_internal.h',
+  './src/nvim/vterm/vterm_internal_defs.h',
   './test/unit/fixtures/vterm_test.h'
 )