diff --git a/ProxyNetworkInterface.php b/ProxyNetworkInterface.php
index ca926a0..5a005c6 100644
--- a/ProxyNetworkInterface.php
+++ b/ProxyNetworkInterface.php
@@ -274,7 +274,7 @@ public function getSession(int $socketId): ?NetworkSession
         return $this->sessions[$socketId] ?? null;
     }
 
-    public function putPacket(int $socketId, ProxyPacket $pk): void
+    public function putPacket(int $socketId, ProxyPacket $pk, int $receiptId = null): void
     {
         $serializer = new ProxyPacketSerializer();
         $serializer->putLInt($socketId);
@@ -289,6 +289,10 @@ public function putPacket(int $socketId, ProxyPacket $pk): void
         } catch (Error $exception) {
             $this->server->getLogger()->debug('Packet was send while the client was already shut down');
         }
+
+        if ($receiptId !== null) { // TODO: check if QUIC supports acks on specific data ;l
+            $this->getSession($socketId)?->handleAckReceipt($receiptId);
+        }
     }
 
     public function createSession(int $socketId, string $ip, int $port): NetworkSession
diff --git a/ProxyPacketSender.php b/ProxyPacketSender.php
index 7a98e1d..4f92b0d 100644
--- a/ProxyPacketSender.php
+++ b/ProxyPacketSender.php
@@ -26,13 +26,13 @@ public function __construct(int $socketId, ProxyNetworkInterface $handler)
         $this->handler = $handler;
     }
 
-    public function send(string $payload, bool $immediate): void
+    public function send(string $payload, bool $immediate, ?int $receiptId): void
     {
         if (!$this->closed) {
             $pk = new ForwardPacket();
             $pk->payload = $payload;
 
-            $this->handler->putPacket($this->socketId, $pk);
+            $this->handler->putPacket($this->socketId, $pk, $receiptId);
         }
     }