diff --git a/src/generator/templates/api/lib/mbuild.mako b/src/generator/templates/api/lib/mbuild.mako
index 7ba7c06a75..4e45eba0e5 100644
--- a/src/generator/templates/api/lib/mbuild.mako
+++ b/src/generator/templates/api/lib/mbuild.mako
@@ -819,7 +819,7 @@ else {
             match req_result {
                 Err(err) => {
                     if let client::Retry::After(d) = dlg.http_error(&err) {
-                        sleep(d);
+                        sleep(d).await;
                         continue;
                     }
                     ${delegate_finish}(false);
@@ -835,7 +835,7 @@ else {
                         let server_response = json::from_str::<serde_json::Value>(&res_body_string).ok();
 
                         if let client::Retry::After(d) = dlg.http_failure(&restored_response, server_response.clone()) {
-                            sleep(d);
+                            sleep(d).await;
                             continue;
                         }