diff --git a/README.md b/README.md
index f961aad..62915fe 100644
--- a/README.md
+++ b/README.md
@@ -102,10 +102,24 @@ export default class SimpleMapPage extends Component {
 
 ### parameters
 
-####apiKey (string)
+####apiKey (string) (_Deprecated use bootstrapURLKeys_)
 
 Google maps api key. (Optional, but your map will be rate-limited with no key)
 
+####bootstrapURLKeys (object)
+
+Example: 
+
+```javascript
+<GoogleMap 
+  bootstrapURLKeys={{
+    key: API_KEY,
+    language: 'ru',
+    ...otherUrlParams,
+  }}
+>
+```
+
 ####defaultCenter (array or object)
 
 `[lat, lng]` or `{ lat: lat, lng: lng}`