diff --git a/pkg/tools/fs/filesystem.go b/pkg/tools/fs/filesystem.go
index 661fd6ca..adc7fa99 100644
--- a/pkg/tools/fs/filesystem.go
+++ b/pkg/tools/fs/filesystem.go
@@ -1064,8 +1064,8 @@ func (r *sandboxFs) execute(path string, fn func(root *os.Root, relPath string)
 		return err
 	}
 
-	// os.Root api on windows only accept forward slashes (/)
-	relPath = filepath.ToSlash(relPath)
+	// os.Root API on Windows only accepts forward slashes (/).
+	relPath = normalizeRootRelPath(relPath)
 
 	return fn(root, relPath)
 }
@@ -1230,6 +1230,17 @@ func buildFs(workspace string, restrict bool, patterns []*regexp.Regexp) fileSys
 	return sandbox
 }
 
+func normalizeRootRelPath(relPath string) string {
+	return normalizeRootRelPathForSeparator(relPath, os.PathSeparator)
+}
+
+func normalizeRootRelPathForSeparator(relPath string, sep rune) string {
+	if sep == '\\' {
+		return strings.ReplaceAll(relPath, `\`, `/`)
+	}
+	return relPath
+}
+
 // Helper to get a safe relative path for os.Root usage
 func getSafeRelPath(workspace, path string) (string, error) {
 	if workspace == "" {
diff --git a/pkg/tools/fs/filesystem_windows_path_test.go b/pkg/tools/fs/filesystem_windows_path_test.go
index 1061f9ff..c30146f3 100644
--- a/pkg/tools/fs/filesystem_windows_path_test.go
+++ b/pkg/tools/fs/filesystem_windows_path_test.go
@@ -1,57 +1,21 @@
 package fstools
 
-import (
-	"io"
-	"os"
-	"path/filepath"
-	"testing"
-)
+import "testing"
 
-func TestSandboxFsReadDirAcceptsOSSpecificRelativePaths(t *testing.T) {
-	workspace := t.TempDir()
-	if err := os.MkdirAll(filepath.Join(workspace, "aaa", "bbb", "ccc"), 0o755); err != nil {
-		t.Fatalf("create nested directory: %v", err)
-	}
-	if err := os.WriteFile(filepath.Join(workspace, "aaa", "bbb", "file.txt"), []byte("hello"), 0o600); err != nil {
-		t.Fatalf("create nested file: %v", err)
-	}
+func TestNormalizeRootRelPathForWindowsSeparator(t *testing.T) {
+	got := normalizeRootRelPathForSeparator(`aaa\bbb\file.txt`, '\\')
+	want := "aaa/bbb/file.txt"
 
-	fsys := &sandboxFs{workspace: workspace}
-	entries, err := fsys.ReadDir(filepath.Join("aaa", "bbb"))
-	if err != nil {
-		t.Fatalf("ReadDir with OS-specific relative path returned error: %v", err)
-	}
-
-	seen := map[string]bool{}
-	for _, entry := range entries {
-		seen[entry.Name()] = true
-	}
-	if !seen["ccc"] || !seen["file.txt"] {
-		t.Fatalf("ReadDir entries = %v, want ccc and file.txt", seen)
+	if got != want {
+		t.Fatalf("normalizeRootRelPathForSeparator() = %q, want %q", got, want)
 	}
 }
 
-func TestSandboxFsOpenAcceptsOSSpecificRelativePaths(t *testing.T) {
-	workspace := t.TempDir()
-	if err := os.MkdirAll(filepath.Join(workspace, "aaa", "bbb"), 0o755); err != nil {
-		t.Fatalf("create nested directory: %v", err)
-	}
-	if err := os.WriteFile(filepath.Join(workspace, "aaa", "bbb", "file.txt"), []byte("hello"), 0o600); err != nil {
-		t.Fatalf("create nested file: %v", err)
-	}
+func TestNormalizeRootRelPathForUnixSeparatorLeavesBackslashUnchanged(t *testing.T) {
+	input := `aaa\bbb\file.txt`
+	got := normalizeRootRelPathForSeparator(input, '/')
 
-	fsys := &sandboxFs{workspace: workspace}
-	file, err := fsys.Open(filepath.Join("aaa", "bbb", "file.txt"))
-	if err != nil {
-		t.Fatalf("Open with OS-specific relative path returned error: %v", err)
-	}
-	defer file.Close()
-
-	data, err := io.ReadAll(file)
-	if err != nil {
-		t.Fatalf("read opened file: %v", err)
-	}
-	if string(data) != "hello" {
-		t.Fatalf("file content = %q, want %q", string(data), "hello")
+	if got != input {
+		t.Fatalf("normalizeRootRelPathForSeparator() = %q, want %q", got, input)
 	}
 }