diff --git a/pkg/configutil/once.go b/pkg/configutil/once.go
index 77daaee5..3d6acd17 100644
--- a/pkg/configutil/once.go
+++ b/pkg/configutil/once.go
@@ -25,17 +25,15 @@ import (
 // If previous config file does not exist, it reads the config from file
 // or return a default config if not found.
 // The returned config is only suitable for read only scenarios for short-lived processes.
-func LoadConfigOnce() (*config.Config, error) {
-	return sync.OnceValues(func() (*config.Config, error) {
-		configInfo, err := config.LoadConfig()
-		if err != nil {
-			return nil, err
-		}
-		// set default value
-		configInfo.SignatureFormat = strings.ToLower(configInfo.SignatureFormat)
-		if configInfo.SignatureFormat == "" {
-			configInfo.SignatureFormat = envelope.JWS
-		}
-		return configInfo, nil
-	})()
-}
+var LoadConfigOnce = sync.OnceValues(func() (*config.Config, error) {
+	configInfo, err := config.LoadConfig()
+	if err != nil {
+		return nil, err
+	}
+	// set default value
+	configInfo.SignatureFormat = strings.ToLower(configInfo.SignatureFormat)
+	if configInfo.SignatureFormat == "" {
+		configInfo.SignatureFormat = envelope.JWS
+	}
+	return configInfo, nil
+})
diff --git a/pkg/configutil/once_test.go b/pkg/configutil/once_test.go
index aba9c25a..5f6ebdef 100644
--- a/pkg/configutil/once_test.go
+++ b/pkg/configutil/once_test.go
@@ -16,7 +16,6 @@ package configutil
 import (
 	"os"
 	"path/filepath"
-	"reflect"
 	"strings"
 	"testing"
 
@@ -32,8 +31,8 @@ func TestLoadConfigOnce(t *testing.T) {
 	if err != nil {
 		t.Fatal("LoadConfigOnce failed.")
 	}
-	if !reflect.DeepEqual(config1, config2) {
-		t.Fatal("Configs differ in content.")
+	if config1 != config2 {
+		t.Fatal("LoadConfigOnce should return the same config.")
 	}
 }
 
@@ -50,8 +49,8 @@ func TestLoadConfigOnceError(t *testing.T) {
 	if err == nil || !strings.Contains(err.Error(), "invalid character") {
 		t.Fatal("LoadConfigOnce should fail.")
 	}
-	_, err = LoadConfigOnce()
-	if err == nil || !strings.Contains(err.Error(), "invalid character") {
-		t.Fatal("LoadConfigOnce should fail.")
+	_, err2 := LoadConfigOnce()
+	if err != err2 {
+		t.Fatal("LoadConfigOnce should return the same error.")
 	}
 }