diff --git a/CHANGES.md b/CHANGES.md
index 12caa2df9..a6bcd56cc 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -12,15 +12,22 @@
   `ServiceRequest::from_request` would not fail and no payload would be generated [#1893]
 * Our `Either` type now uses `Left`/`Right` variants (instead of `A`/`B`) [#1894]
 
+### Fixed
+* Multiple calls `App::data` with the same type now keeps the latest call's data. [#1906]
+
 ### Removed
 * Public field of `web::Path` has been made private. [#1894]
 * Public field of `web::Query` has been made private. [#1894]
 * `TestRequest::with_header`; use `TestRequest::default().insert_header()`. [#1869]
+* `AppService::set_service_data`; for custom HTTP service factories adding application data, use the
+  layered data model by calling `ServiceRequest::add_data_container` when handling
+  requests instead. [#1906]
 
 [#1891]: https://github.com/actix/actix-web/pull/1891
 [#1893]: https://github.com/actix/actix-web/pull/1893
 [#1894]: https://github.com/actix/actix-web/pull/1894
 [#1869]: https://github.com/actix/actix-web/pull/1869
+[#1906]: https://github.com/actix/actix-web/pull/1906
 
 
 ## 4.0.0-beta.1 - 2021-01-07
diff --git a/src/service.rs b/src/service.rs
index d4fa4acca..596eedd7f 100644
--- a/src/service.rs
+++ b/src/service.rs
@@ -231,8 +231,10 @@ impl ServiceRequest {
         self.payload = payload;
     }
 
-    #[doc(hidden)]
-    /// Add app data container to request's resolution set.
+    /// Add data container to request's resolution set.
+    ///
+    /// In middleware, prefer [`extensions_mut`](ServiceRequest::extensions_mut) for request-local
+    /// data since it is assumed that the same app data is presented for every request.
     pub fn add_data_container(&mut self, extensions: Rc<Extensions>) {
         Rc::get_mut(&mut (self.req).inner)
             .unwrap()