diff --git a/lib/aliyunsdkcore/roa_client.rb b/lib/aliyunsdkcore/roa_client.rb
index 92473f9..d54cb44 100644
--- a/lib/aliyunsdkcore/roa_client.rb
+++ b/lib/aliyunsdkcore/roa_client.rb
@@ -1,6 +1,5 @@
 require 'faraday'
 require 'securerandom'
-require 'active_support/all'
 
 module AliyunSDKCore
 
@@ -21,7 +20,9 @@ def initialize(config)
 
     def request(method:, uri:, params: {}, body: {}, headers: {}, options: {})
       # :"Content-Type" => "application/json" to "content-type" => "application/json"
-      headers.deep_transform_keys! { |key| key.to_s.downcase }
+      headers.each_with_object({}) do |(key, value), result|
+        result[key.to_s.downcase] = value
+      end
       mix_headers = default_headers.merge(headers)
 
       response = connection.send(method.downcase) do |request|
diff --git a/spec/roa_client_spec.rb b/spec/roa_client_spec.rb
index 4d4cca5..af6492e 100644
--- a/spec/roa_client_spec.rb
+++ b/spec/roa_client_spec.rb
@@ -221,7 +221,7 @@
       it 'should ok' do
         stub_request(:get, "https://ros.aliyuncs.com/")
           .to_return(status: 200, headers: { 'content-type': 'application/json' }, body: { ok: true }.to_json)
-        response = roa_client.put(uri: '/', body: 'text')
+        response = roa_client.put(uri: '/', body: 'text', headers: {'Content-Type': 'application/json'})
         expect(response.body).to eq('{"ok":true}')
       end
     end