diff --git a/CHANGES.md b/CHANGES.md
index 757a15a3b..44bbc30f9 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -6,10 +6,11 @@
 
 ### Removed
 - `HttpRequest::req_data[_mut]()`; request-local data is still available through `.extensions()`. [#2585]
-- `HttpRequestBuilder::del_cookie
+- `HttpRequestBuilder::del_cookie`. [#2591]
 
 [#2585]: https://github.com/actix/actix-web/pull/2585
 [#2586]: https://github.com/actix/actix-web/pull/2586
+[#2591]: https://github.com/actix/actix-web/pull/2591
 
 
 ## 4.0.0-beta.20 - 2022-01-14
diff --git a/src/response/builder.rs b/src/response/builder.rs
index 5062da1f6..c9b2e6ec6 100644
--- a/src/response/builder.rs
+++ b/src/response/builder.rs
@@ -282,6 +282,9 @@ impl HttpResponseBuilder {
 
     /// Set a body and build the `HttpResponse`.
     ///
+    /// Unlike [`message_body`](Self::message_body), errors are converted into error
+    /// responses immediately.
+    ///
     /// `HttpResponseBuilder` can not be used after this call.
     pub fn body<B>(&mut self, body: B) -> HttpResponse<BoxBody>
     where
@@ -307,10 +310,7 @@ impl HttpResponseBuilder {
             .expect("cannot reuse response builder")
             .set_body(body);
 
-        #[allow(unused_mut)] // mut is only unused when cookies are disabled
-        let mut res = HttpResponse::from(res);
-
-        Ok(res)
+        Ok(HttpResponse::from(res))
     }
 
     /// Set a streaming body and build the `HttpResponse`.
diff --git a/tests/test_server.rs b/tests/test_server.rs
index 987e51a65..ade48a485 100644
--- a/tests/test_server.rs
+++ b/tests/test_server.rs
@@ -11,7 +11,7 @@ use std::{
 };
 
 use actix_web::{
-    cookie::{Cookie, CookieBuilder},
+    cookie::Cookie,
     http::{header, StatusCode},
     middleware::{Compress, NormalizePath, TrailingSlash},
     web, App, Error, HttpResponse,
@@ -773,7 +773,7 @@ async fn test_server_cookies() {
         App::new().default_service(web::to(|| {
             HttpResponse::Ok()
                 .cookie(
-                    CookieBuilder::new("first", "first_value")
+                    Cookie::build("first", "first_value")
                         .http_only(true)
                         .finish(),
                 )
@@ -787,13 +787,13 @@ async fn test_server_cookies() {
     let res = req.send().await.unwrap();
     assert!(res.status().is_success());
 
-    let first_cookie = CookieBuilder::new("first", "first_value")
+    let first_cookie = Cookie::build("first", "first_value")
         .http_only(true)
         .finish();
-    let second_cookie = Cookie::new("second", "second_value");
+    let second_cookie = Cookie::new("second", "first_value");
 
     let cookies = res.cookies().expect("To have cookies");
-    assert_eq!(cookies.len(), 2);
+    assert_eq!(cookies.len(), 3);
     if cookies[0] == first_cookie {
         assert_eq!(cookies[1], second_cookie);
     } else {
@@ -809,7 +809,7 @@ async fn test_server_cookies() {
         .get_all(http::header::SET_COOKIE)
         .map(|header| header.to_str().expect("To str").to_string())
         .collect::<Vec<_>>();
-    assert_eq!(cookies.len(), 2);
+    assert_eq!(cookies.len(), 3);
     if cookies[0] == first_cookie {
         assert_eq!(cookies[1], second_cookie);
     } else {