diff --git a/credentials/ecs_ram_role.go b/credentials/ecs_ram_role.go
index 69da093..00aaada 100644
--- a/credentials/ecs_ram_role.go
+++ b/credentials/ecs_ram_role.go
@@ -36,18 +36,6 @@ type ecsRAMRoleResponse struct {
 	Expiration      string `json:"Expiration" xml:"Expiration"`
 }
 
-func newEcsRAMRoleCredential(roleName string, inAdvanceScale float64, runtime *utils.Runtime) *EcsRAMRoleCredential {
-	credentialUpdater := new(credentialUpdater)
-	if inAdvanceScale < 1 && inAdvanceScale > 0 {
-		credentialUpdater.inAdvanceScale = inAdvanceScale
-	}
-	return &EcsRAMRoleCredential{
-		RoleName:          roleName,
-		credentialUpdater: credentialUpdater,
-		runtime:           runtime,
-	}
-}
-
 func newEcsRAMRoleCredentialWithEnableIMDSv2(roleName string, enableIMDSv2 bool, metadataTokenDuration int, inAdvanceScale float64, runtime *utils.Runtime) *EcsRAMRoleCredential {
 	credentialUpdater := new(credentialUpdater)
 	if inAdvanceScale < 1 && inAdvanceScale > 0 {
diff --git a/credentials/ecs_ram_role_test.go b/credentials/ecs_ram_role_test.go
index 39f9652..a9e67d3 100644
--- a/credentials/ecs_ram_role_test.go
+++ b/credentials/ecs_ram_role_test.go
@@ -9,7 +9,13 @@ import (
 )
 
 func Test_EcsRAmRoleCredential(t *testing.T) {
-	auth := newEcsRAMRoleCredential("go sdk", 0.5, nil)
+	credentialUpdater := new(credentialUpdater)
+	credentialUpdater.inAdvanceScale = 0.5
+	auth := &EcsRAMRoleCredential{
+		RoleName:          "go sdk",
+		credentialUpdater: credentialUpdater,
+		runtime:           nil,
+	}
 	origTestHookDo := hookDo
 	defer func() { hookDo = origTestHookDo }()