diff --git a/internal/third_party/dep/fs/fs_test.go b/internal/third_party/dep/fs/fs_test.go
index 909fa4d00..22c59868c 100644
--- a/internal/third_party/dep/fs/fs_test.go
+++ b/internal/third_party/dep/fs/fs_test.go
@@ -33,7 +33,6 @@ package fs
 
 import (
 	"os"
-	"os/exec"
 	"path/filepath"
 	"runtime"
 	"testing"
@@ -355,19 +354,6 @@ func TestCopyFile(t *testing.T) {
 	}
 }
 
-func cleanUpDir(dir string) {
-	// NOTE(mattn): It seems that sometimes git.exe is not dead
-	// when cleanUpDir() is called. But we do not know any way to wait for it.
-	if runtime.GOOS == "windows" {
-		mu.Lock()
-		exec.Command(`taskkill`, `/F`, `/IM`, `git.exe`).Run()
-		mu.Unlock()
-	}
-	if dir != "" {
-		os.RemoveAll(dir)
-	}
-}
-
 func TestCopyFileSymlink(t *testing.T) {
 	tempdir := t.TempDir()