diff --git a/src/network/network_udp.cpp b/src/network/network_udp.cpp
index 58d0f31c5e..94a677245e 100644
--- a/src/network/network_udp.cpp
+++ b/src/network/network_udp.cpp
@@ -678,6 +678,8 @@ void NetworkUDPClose()
 /** Receive the UDP packets. */
 void NetworkBackgroundUDPLoop()
 {
+	_network_udp_mutex->BeginCritical();
+
 	if (_network_udp_server) {
 		_udp_server_socket->ReceivePackets();
 		_udp_master_socket->ReceivePackets();
@@ -685,6 +687,8 @@ void NetworkBackgroundUDPLoop()
 		_udp_client_socket->ReceivePackets();
 		if (_network_udp_broadcast > 0) _network_udp_broadcast--;
 	}
+
+	_network_udp_mutex->EndCritical();
 }
 
 #endif /* ENABLE_NETWORK */