diff --git a/include/seastar/core/prometheus.hh b/include/seastar/core/prometheus.hh
index 2505828051..8ae5a3f1ad 100644
--- a/include/seastar/core/prometheus.hh
+++ b/include/seastar/core/prometheus.hh
@@ -54,6 +54,16 @@ future<> start(httpd::http_server_control& http_server, config ctx);
 future<> add_prometheus_routes(distributed<httpd::http_server>& server, config ctx);
 future<> add_prometheus_routes(httpd::http_server& server, config ctx);
 /// @}
+
+namespace details {
+using filter_t = std::function<bool(const metrics::impl::labels_type&)>;
+
+class test_access {
+    future<> write_body(config cfg, sstring metric_family_name, bool prefix, bool show_help, bool enable_aggregation, filter_t filter, output_stream<char>&& s);
+
+    friend struct metrics_perf_fixture;
+};
+}
 SEASTAR_MODULE_EXPORT_END
 }
 }
diff --git a/src/core/prometheus.cc b/src/core/prometheus.cc
index 23c6ff557d..6be1e86be0 100644
--- a/src/core/prometheus.cc
+++ b/src/core/prometheus.cc
@@ -924,24 +924,33 @@ class metrics_handler : public httpd::handler_base  {
         bool show_help = req->get_query_param("__help__") != "false";
         bool enable_aggregation = req->get_query_param("__aggregate__") != "false";
         std::function<bool(const mi::labels_type&)> filter = make_filter(*req);
-        rep->write_body(is_protobuf_format ? "proto" : "txt", [this, is_protobuf_format, metric_family_name, prefix, show_help, enable_aggregation, filter] (output_stream<char>&& s) {
-            return do_with(metrics_families_per_shard(), output_stream<char>(std::move(s)),
-                    [this, is_protobuf_format, prefix, &metric_family_name, show_help, enable_aggregation, filter] (metrics_families_per_shard& families, output_stream<char>& s) mutable {
-                return get_map_value(families).then([&s, &families, this, is_protobuf_format, prefix, &metric_family_name, show_help, enable_aggregation, filter]() mutable {
-                    return do_with(get_range(families, metric_family_name, prefix),
-                            [&s, this, is_protobuf_format, show_help, enable_aggregation, filter](metric_family_range& m) {
-                        return (is_protobuf_format) ?  write_protobuf_representation(s, _ctx, m, enable_aggregation, filter) :
-                                write_text_representation(s, _ctx, m, show_help, enable_aggregation, filter);
-                    });
-                }).finally([&s] () mutable {
-                    return s.close();
-                });
-            });
+        rep->write_body(is_protobuf_format ? "proto" : "txt", [this, is_protobuf_format, metric_family_name, prefix, show_help, enable_aggregation, filter](output_stream<char>&& s) {
+            return write_body(is_protobuf_format, metric_family_name, prefix, show_help, enable_aggregation, filter, std::move(s));
         });
         return make_ready_future<std::unique_ptr<http::reply>>(std::move(rep));
     }
+
+private:
+    future<> write_body(bool is_protobuf_format, sstring metric_family_name, bool prefix, bool show_help, bool enable_aggregation, details::filter_t filter, output_stream<char>&& out_stream) {
+        auto s = std::move(out_stream);
+        auto families = metrics_families_per_shard{};
+        co_await get_map_value(families);
+
+        auto m = get_range(families, metric_family_name, prefix);
+
+        co_return co_await ((is_protobuf_format) ? write_protobuf_representation(s, _ctx, m, enable_aggregation, filter) : write_text_representation(s, _ctx, m, show_help, enable_aggregation, filter)).finally([&s] { return s.close(); });
+
+    }
+
+    friend details::test_access;
 };
 
+future<> details::test_access::write_body(config cfg, sstring metric_family_name, bool prefix, bool show_help, bool enable_aggregation, filter_t filter, output_stream<char>&& s) {
+    metrics_handler handler(std::move(cfg));
+
+    co_return co_await handler.write_body(cfg.allow_protobuf, metric_family_name, prefix, show_help, enable_aggregation, filter, std::move(s));
+}
+
 std::function<bool(const mi::labels_type&)> metrics_handler::_true_function = [](const mi::labels_type&) {
     return true;
 };