diff --git a/peer.c b/peer.c
index 2cba2a6..f9d73fc 100644
--- a/peer.c
+++ b/peer.c
@@ -482,7 +482,7 @@ enet_peer_queue_acknowledgement (ENetPeer * peer, const ENetProtocol * command,
         if (command -> header.reliableSequenceNumber < channel -> incomingReliableSequenceNumber)
            reliableWindow += ENET_PEER_RELIABLE_WINDOWS;
 
-        if (reliableWindow < currentWindow || reliableWindow >= currentWindow + ENET_PEER_FREE_RELIABLE_WINDOWS - 1)
+        if (reliableWindow >= currentWindow + ENET_PEER_FREE_RELIABLE_WINDOWS - 1 && reliableWindow <= currentWindow + ENET_PEER_FREE_RELIABLE_WINDOWS)
           return NULL;
     }