diff --git a/src/cmd/go/internal/modload/stat_openfile.go b/src/cmd/go/internal/modload/stat_openfile.go
deleted file mode 100644
index 5773073d903..00000000000
--- a/src/cmd/go/internal/modload/stat_openfile.go
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build (js && wasm) || plan9
-
-// On plan9, per http://9p.io/magic/man2html/2/access: “Since file permissions
-// are checked by the server and group information is not known to the client,
-// access must open the file to check permissions.”
-//
-// js,wasm is similar, in that it does not define syscall.Access.
-
-package modload
-
-import (
-	"io/fs"
-	"os"
-)
-
-// hasWritePerm reports whether the current user has permission to write to the
-// file with the given info.
-func hasWritePerm(path string, _ fs.FileInfo) bool {
-	if f, err := os.OpenFile(path, os.O_WRONLY, 0); err == nil {
-		f.Close()
-		return true
-	}
-	return false
-}
diff --git a/src/cmd/go/internal/modload/stat_unix.go b/src/cmd/go/internal/modload/stat_unix.go
deleted file mode 100644
index a0d5f4d2476..00000000000
--- a/src/cmd/go/internal/modload/stat_unix.go
+++ /dev/null
@@ -1,32 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build unix
-
-package modload
-
-import (
-	"io/fs"
-	"os"
-	"syscall"
-)
-
-// hasWritePerm reports whether the current user has permission to write to the
-// file with the given info.
-//
-// Although the root user on most Unix systems can write to files even without
-// permission, hasWritePerm reports false if no appropriate permission bit is
-// set even if the current user is root.
-func hasWritePerm(path string, fi fs.FileInfo) bool {
-	if os.Getuid() == 0 {
-		// The root user can access any file, but we still want to default to
-		// read-only mode if the go.mod file is marked as globally non-writable.
-		// (If the user really intends not to be in readonly mode, they can
-		// pass -mod=mod explicitly.)
-		return fi.Mode()&0222 != 0
-	}
-
-	const W_OK = 0x2
-	return syscall.Access(path, W_OK) == nil
-}
diff --git a/src/cmd/go/internal/modload/stat_windows.go b/src/cmd/go/internal/modload/stat_windows.go
deleted file mode 100644
index f29a99165e5..00000000000
--- a/src/cmd/go/internal/modload/stat_windows.go
+++ /dev/null
@@ -1,21 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build windows
-
-package modload
-
-import "io/fs"
-
-// hasWritePerm reports whether the current user has permission to write to the
-// file with the given info.
-func hasWritePerm(_ string, fi fs.FileInfo) bool {
-	// Windows has a read-only attribute independent of ACLs, so use that to
-	// determine whether the file is intended to be overwritten.
-	//
-	// Per https://golang.org/pkg/os/#Chmod:
-	// “On Windows, only the 0200 bit (owner writable) of mode is used; it
-	// controls whether the file's read-only attribute is set or cleared.”
-	return fi.Mode()&0200 != 0
-}