diff --git a/src/network/network.cpp b/src/network/network.cpp
index 1d5563c3d9..f4640191c8 100644
--- a/src/network/network.cpp
+++ b/src/network/network.cpp
@@ -74,19 +74,12 @@ uint32 _sync_seed_2;                  ///< Second part of the seed.
 #endif
 uint32 _sync_frame;                   ///< The frame to perform the sync check.
 bool _network_first_time;             ///< Whether we have finished joining or not.
-bool _network_udp_server;             ///< Is the UDP server started?
-uint16 _network_udp_broadcast;        ///< Timeout for the UDP broadcasts.
-uint8 _network_advertise_retries;     ///< The number of advertisement retries we did.
 CompanyMask _network_company_passworded; ///< Bitmask of the password status of all companies.
 
 /* Check whether NETWORK_NUM_LANDSCAPES is still in sync with NUM_LANDSCAPE */
 static_assert((int)NETWORK_NUM_LANDSCAPES == (int)NUM_LANDSCAPE);
 static_assert((int)NETWORK_COMPANY_NAME_LENGTH == MAX_LENGTH_COMPANY_NAME_CHARS * MAX_CHAR_LENGTH);
 
-extern NetworkUDPSocketHandler *_udp_client_socket; ///< udp client socket
-extern NetworkUDPSocketHandler *_udp_server_socket; ///< udp server socket
-extern NetworkUDPSocketHandler *_udp_master_socket; ///< udp master socket
-
 /** The amount of clients connected */
 byte _network_clients_connected = 0;
 
@@ -724,7 +717,7 @@ bool NetworkServerStart()
 
 	/* Try to start UDP-server */
 	DEBUG(net, 1, "starting listeners for incoming server queries");
-	_network_udp_server = _udp_server_socket->Listen();
+	NetworkUDPServerListen();
 
 	_network_company_states = CallocT<NetworkCompanyState>(MAX_COMPANIES);
 	_network_server = true;
@@ -1060,7 +1053,6 @@ void NetworkStartUp()
 	_network_available = NetworkCoreInitialize();
 	_network_dedicated = false;
 	_network_need_advertise = true;
-	_network_advertise_retries = 0;
 
 	/* Generate an server id when there is none yet */
 	if (StrEmpty(_settings_client.network.network_id)) NetworkGenerateServerId();
diff --git a/src/network/network_internal.h b/src/network/network_internal.h
index 8cae502e10..290922f385 100644
--- a/src/network/network_internal.h
+++ b/src/network/network_internal.h
@@ -126,11 +126,6 @@ extern uint32 _network_join_bytes_total;
 
 extern uint8 _network_reconnect;
 
-extern bool _network_udp_server;
-extern uint16 _network_udp_broadcast;
-
-extern uint8 _network_advertise_retries;
-
 extern CompanyMask _network_company_passworded;
 
 void NetworkTCPQueryServer(NetworkAddress address);
diff --git a/src/network/network_udp.cpp b/src/network/network_udp.cpp
index 99939fab44..e4276c58f1 100644
--- a/src/network/network_udp.cpp
+++ b/src/network/network_udp.cpp
@@ -47,6 +47,10 @@ NetworkUDPSocketHandler *_udp_client_socket = nullptr; ///< udp client socket
 NetworkUDPSocketHandler *_udp_server_socket = nullptr; ///< udp server socket
 NetworkUDPSocketHandler *_udp_master_socket = nullptr; ///< udp master socket
 
+static bool _network_udp_server;         ///< Is the UDP server started?
+static uint16 _network_udp_broadcast;    ///< Timeout for the UDP broadcasts.
+static uint8 _network_advertise_retries; ///< The number of advertisement retries we did.
+
 /**
  * Helper function doing the actual work for querying the server.
  * @param address The address of the server.
@@ -622,6 +626,13 @@ void NetworkUDPInitialize()
 
 	_network_udp_server = false;
 	_network_udp_broadcast = 0;
+	_network_advertise_retries = 0;
+}
+
+/** Start the listening of the UDP server component. */
+void NetworkUDPServerListen()
+{
+	_network_udp_server = _udp_server_socket->Listen();
 }
 
 /** Close all UDP related stuff. */
diff --git a/src/network/network_udp.h b/src/network/network_udp.h
index c042bea404..189657bc87 100644
--- a/src/network/network_udp.h
+++ b/src/network/network_udp.h
@@ -19,6 +19,7 @@ void NetworkUDPQueryServer(NetworkAddress address, bool manually = false);
 void NetworkUDPAdvertise();
 void NetworkUDPRemoveAdvertise(bool blocking);
 void NetworkUDPClose();
+void NetworkUDPServerListen();
 void NetworkBackgroundUDPLoop();
 
 #endif /* NETWORK_UDP_H */