diff --git a/gpapi/config.py b/gpapi/config.py
index 4e79e34..432d8df 100644
--- a/gpapi/config.py
+++ b/gpapi/config.py
@@ -102,30 +102,19 @@ class DeviceBuilder(object):
             headers['device'] = "{0:x}".format(gsfid)
         return headers
 
-    def getAuthParams(self, email, passwd):
-        return {"Email": email,
-                "EncryptedPasswd": passwd,
-                "accountType": ACCOUNT,
-                "has_permission": "1",
-                "source": "android",
-                "device_country": self.locale[0:2],
-                "service": "androidmarket",
-                "app": "com.android.vending",
-                "lang": self.locale,
-                "sdk_version": self.device['build.version.sdk_int']}
-
     def getLoginParams(self, email, encrypted_passwd):
         return {"Email": email,
                 "EncryptedPasswd": encrypted_passwd,
-                "service": "ac2dm",
                 "add_account": "1",
                 "accountType": ACCOUNT,
+                "google_play_services_version": self.device.get('gsf.version'),
                 "has_permission": "1",
-                "app": "com.google.android.gsf",
                 "source": "android",
                 "device_country": self.locale[0:2],
                 "lang": self.locale,
-                "sdk_version": self.device.get('build.version.sdk_int')}
+                "sdk_version": self.device.get('build.version.sdk_int'),
+                "client_sig": "38918a453d07199354f8b19af05ec6562ced5788",
+                "callerSig": "38918a453d07199354f8b19af05ec6562ced5788"}
 
     def getAndroidCheckinRequest(self):
         request = googleplay_pb2.AndroidCheckinRequest()
diff --git a/gpapi/googleplay.py b/gpapi/googleplay.py
index 4d9de84..4ff7e1a 100644
--- a/gpapi/googleplay.py
+++ b/gpapi/googleplay.py
@@ -158,6 +158,11 @@ class GooglePlayAPI(object):
             encryptedPass = self.encrypt_password(email, password).decode('utf-8')
             # AC2DM token
             params = self.deviceBuilder.getLoginParams(email, encryptedPass)
+            params['service'] = 'ac2dm'
+            params['add_account'] = '1'
+            params['callerPkg'] = 'com.google.android.gms'
+            headers = self.deviceBuilder.getAuthHeaders(self.gsfId)
+            headers['app'] = 'com.google.android.gsm'
             response = requests.post(self.AUTHURL, data=params, verify=ssl_verify,
                                      proxies=self.proxies_config)
             data = response.text.split()
@@ -195,8 +200,11 @@ class GooglePlayAPI(object):
             raise LoginError('Either (email,pass) or (gsfId, authSubToken) is needed')
 
     def getAuthSubToken(self, email, passwd):
-        requestParams = self.deviceBuilder.getAuthParams(email, passwd)
+        requestParams = self.deviceBuilder.getLoginParams(email, passwd)
+        requestParams['service'] = 'androidmarket'
+        requestParams['app'] = 'com.android.vending'
         headers = self.deviceBuilder.getAuthHeaders(self.gsfId)
+        headers['app'] = 'com.android.vending'
         response = requests.post(self.AUTHURL,
                                  data=requestParams,
                                  verify=ssl_verify,
@@ -221,16 +229,17 @@ class GooglePlayAPI(object):
             raise LoginError("auth token not found.")
 
     def getSecondRoundToken(self, first_token, params):
+        if self.gsfId is not None:
+            params['androidId'] = "{0:x}".format(self.gsfId)
         params['Token'] = first_token
-        params['service'] = 'androidmarket'
         params['check_email'] = '1'
         params['token_request_options'] = 'CAA4AQ=='
         params['system_partition'] = '1'
         params['_opt_is_called_from_account_manager'] = '1'
-        params['google_play_services_version'] = '11518448'
         params.pop('Email')
         params.pop('EncryptedPasswd')
         headers = self.deviceBuilder.getAuthHeaders(self.gsfId)
+        headers['app'] = 'com.android.vending'
         response = requests.post(self.AUTHURL,
                                  data=params,
                                  headers=headers,