diff --git a/src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.cpp b/src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.cpp
index c999e78117..c68822f78f 100644
--- a/src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.cpp
+++ b/src/add-ons/kernel/network/protocols/tcp/TCPEndpoint.cpp
@@ -2492,6 +2492,8 @@ TCPEndpoint::_PersistTimer(net_timer* timer, void* _endpoint)
 	// the timer might not have been canceled early enough
 	if (endpoint->State() == CLOSED)
 		return;
+	if (endpoint->fSendQueue.Available(endpoint->fSendNext) == 0)
+		return;
 
 	endpoint->_SendQueued(true);
 }
@@ -2510,6 +2512,8 @@ TCPEndpoint::_DelayedAcknowledgeTimer(net_timer* timer, void* _endpoint)
 	// the timer might not have been canceled early enough
 	if (endpoint->State() == CLOSED)
 		return;
+	if (endpoint->fLastAcknowledgeSent == endpoint->fReceiveNext)
+		return;
 
 	endpoint->SendAcknowledge(true);
 }