diff --git a/codegen/src/ops.rs b/codegen/src/ops.rs
index 1123d442..07cd0d8b 100644
--- a/codegen/src/ops.rs
+++ b/codegen/src/ops.rs
@@ -661,7 +661,13 @@ fn codegen_op_http_call(op: &Operation) {
         g!("let fut = async move {{");
         g!("let result = s3.{method}(s3_req).await;");
         g!("match result {{");
-        g!("Ok(s3_resp) => Self::serialize_http(s3_resp.output).unwrap(),");
+        glines![
+            "Ok(s3_resp) => {
+                let mut resp = Self::serialize_http(s3_resp.output).unwrap();
+                resp.headers.extend(s3_resp.headers);
+                resp
+            }"
+        ];
         g!("Err(err) => super::serialize_error_no_decl(err).unwrap(),");
         g!("}}");
         g!("}};");
diff --git a/crates/s3s/src/keep_alive_body.rs b/crates/s3s/src/keep_alive_body.rs
index ff55b379..a3646135 100644
--- a/crates/s3s/src/keep_alive_body.rs
+++ b/crates/s3s/src/keep_alive_body.rs
@@ -82,4 +82,8 @@ where
             }
         }
     }
+
+    fn is_end_stream(&self) -> bool {
+        self.done
+    }
 }
diff --git a/crates/s3s/src/ops/generated.rs b/crates/s3s/src/ops/generated.rs
index a0045db5..7c19e1ef 100644
--- a/crates/s3s/src/ops/generated.rs
+++ b/crates/s3s/src/ops/generated.rs
@@ -556,7 +556,11 @@ impl super::Operation for CompleteMultipartUpload {
         let fut = async move {
             let result = s3.complete_multipart_upload(s3_req).await;
             match result {
-                Ok(s3_resp) => Self::serialize_http(s3_resp.output).unwrap(),
+                Ok(s3_resp) => {
+                    let mut resp = Self::serialize_http(s3_resp.output).unwrap();
+                    resp.headers.extend(s3_resp.headers);
+                    resp
+                }
                 Err(err) => super::serialize_error_no_decl(err).unwrap(),
             }
         };