diff --git a/pyicloud/services/findmyiphone.py b/pyicloud/services/findmyiphone.py
index e3e8564..1d9971c 100755
--- a/pyicloud/services/findmyiphone.py
+++ b/pyicloud/services/findmyiphone.py
@@ -35,7 +35,19 @@ class FindMyiPhoneServiceManager(object):
         """
         host = self._service_root.split('//')[1].split(':')[0]
         self.session.headers.update({'host': host})
-        req = self.session.post(self._fmip_refresh_url, params=self.params, data='{"clientContext":{"fmly":true,"shouldLocate":true,"selectedDevice":"all"}}')
+        req = self.session.post(
+            self._fmip_refresh_url,
+            params=self.params,
+            data=json.dumps(
+                {
+                    'clientContext': {
+                        'fmly': True,
+                        'shouldLocate': True,
+                        'selectedDevice': 'all',
+                    }
+                }
+            )
+        )
         self.response = req.json()
 
         for device_info in self.response['content']: