diff --git a/internal/build/size_report.go b/internal/build/size_report.go
index 95b1c1d0..e91dbf49 100644
--- a/internal/build/size_report.go
+++ b/internal/build/size_report.go
@@ -4,16 +4,16 @@ import (
 	"bufio"
 	"bytes"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"io"
 	"math"
 	"os"
-	"os/exec"
 	"path/filepath"
 	"sort"
 	"strconv"
 	"strings"
+
+	"github.com/goplus/llgo/xtool/env/llvm"
 )
 
 type sectionKind int
@@ -132,7 +132,10 @@ func reportBinarySize(path, format, level string, pkgs []Package) error {
 }
 
 func collectBinarySize(path string, pkgs []Package, level string) (*sizeReport, error) {
-	cmd := exec.Command("llvm-readelf", "--all", path)
+	cmd, err := llvm.New("").Readelf("--elf-output-style=LLVM", "--all", path)
+	if err != nil {
+		return nil, fmt.Errorf("llvm-readelf: %w", err)
+	}
 	var stderr bytes.Buffer
 	cmd.Stderr = &stderr
 	stdout, err := cmd.StdoutPipe()
@@ -574,8 +577,14 @@ func ensureSizeReporting(conf *Config) error {
 	default:
 		return fmt.Errorf("invalid size level %q (valid: full,module,package)", conf.SizeLevel)
 	}
-	if _, err := exec.LookPath("llvm-readelf"); err != nil {
-		return errors.New("llvm-readelf not found in PATH")
+	cmd, err := llvm.New("").Readelf("--version")
+	if err != nil {
+		return fmt.Errorf("llvm-readelf not available: %w", err)
+	}
+	cmd.Stdout = io.Discard
+	cmd.Stderr = io.Discard
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("llvm-readelf not available: %w", err)
 	}
 	return nil
 }
diff --git a/xtool/env/llvm/llvm.go b/xtool/env/llvm/llvm.go
index 56771908..90539a2f 100644
--- a/xtool/env/llvm/llvm.go
+++ b/xtool/env/llvm/llvm.go
@@ -17,9 +17,11 @@
 package llvm
 
 import (
+	"fmt"
 	"os"
 	"os/exec"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"github.com/goplus/llgo/internal/env"
@@ -108,4 +110,62 @@ func (e *Env) InstallNameTool() *install_name_tool.Cmd {
 	return install_name_tool.New(bin)
 }
 
+// Readelf returns a command to execute llvm-readelf with given arguments.
+func (e *Env) Readelf(args ...string) (*exec.Cmd, error) {
+	path, err := e.toolPath("llvm-readelf")
+	if err != nil {
+		return nil, err
+	}
+	return exec.Command(path, args...), nil
+}
+
+func (e *Env) toolPath(base string) (string, error) {
+	if tool := searchTool(e.binDir, base); tool != "" {
+		return tool, nil
+	}
+	if tool, err := exec.LookPath(base); err == nil {
+		return tool, nil
+	}
+	if tool := searchToolInPath(base); tool != "" {
+		return tool, nil
+	}
+	return "", fmt.Errorf("%s not found", base)
+}
+
+func searchTool(dir, base string) string {
+	if dir == "" {
+		return ""
+	}
+	candidate := filepath.Join(dir, base)
+	if isExecutable(candidate) {
+		return candidate
+	}
+	pattern := filepath.Join(dir, base+"-*")
+	matches, _ := filepath.Glob(pattern)
+	sort.Sort(sort.Reverse(sort.StringSlice(matches)))
+	for _, match := range matches {
+		if isExecutable(match) {
+			return match
+		}
+	}
+	return ""
+}
+
+func searchToolInPath(base string) string {
+	for _, dir := range filepath.SplitList(os.Getenv("PATH")) {
+		if tool := searchTool(dir, base); tool != "" {
+			return tool
+		}
+	}
+	return ""
+}
+
+func isExecutable(path string) bool {
+	if path == "" {
+		return false
+	}
+	info, err := os.Stat(path)
+	return err == nil && !info.IsDir()
+}
+
 // -----------------------------------------------------------------------------