diff --git a/libraries/networking/src/udt/Connection.cpp b/libraries/networking/src/udt/Connection.cpp
index dd34a2bad2..5c3e1846ce 100644
--- a/libraries/networking/src/udt/Connection.cpp
+++ b/libraries/networking/src/udt/Connection.cpp
@@ -129,7 +129,7 @@ void Connection::sendACK(bool wasCausedBySyncTimeout) {
     ackPacket->reset(); // We need to reset it every time.
     
     // pack in the ACK sub-sequence number
-    ackPacket->writePrimitive(_currentACKSubSequenceNumber++);
+    ackPacket->writePrimitive(++_currentACKSubSequenceNumber);
     
     // pack in the ACK number
     ackPacket->writePrimitive(nextACKNumber);