Index: source/network/NetClient.cpp
===================================================================
--- source/network/NetClient.cpp
+++ source/network/NetClient.cpp
@@ -476,6 +476,8 @@
 		JS::RootedValue msg(cx);
 		GetScriptInterface().Eval("({'type':'netstatus','status':'waiting_for_players'})", &msg);
 		PushGuiMessage(msg);
+		// We allowed longer timeouts during loading, so now return them to normal.
+		m_Session->SetLongTimeout(false);
 	}
 
 	CLoadedGameMessage loaded;
@@ -680,6 +682,9 @@
 	JSContext* cx = client->GetScriptInterface().GetContext();
 	JSAutoRequest rq(cx);
 
+	// Prevent player drops during loading.
+	client->m_Session->SetLongTimeout(true);
+
 	// Find the player assigned to our GUID
 	int player = -1;
 	if (client->m_PlayerAssignments.find(client->m_GUID) != client->m_PlayerAssignments.end())
@@ -704,6 +709,9 @@
 
 	CNetClient* client = (CNetClient*)context;
 
+	// Prevent player drops during loading.
+	client->m_Session->SetLongTimeout(true);
+
 	// The server wants us to start downloading the game state from it, so do so
 	client->m_Session->GetFileTransferer().StartTask(
 		shared_ptr<CNetFileReceiveTask>(new CNetFileReceiveTask_ClientRejoin(*client))
@@ -879,8 +887,13 @@
 
 	// If we have rejoined an in progress game, send the rejoined message to the server.
 	if (client->m_Rejoin)
+	{
 		client->SendRejoinedMessage();
 
+		// We allowed longer timeouts during loading, so now return them to normal.
+		client->m_Session->SetLongTimeout(false);
+	}
+
 	return true;
 }
 
Index: source/network/NetServer.cpp
===================================================================
--- source/network/NetServer.cpp
+++ source/network/NetServer.cpp
@@ -1101,6 +1101,8 @@
 		);
 
 		session->SetNextState(NSS_JOIN_SYNCING);
+		// Prevent player drops during loading.
+		session->SetLongTimeout(true);
 	}
 
 	return true;
@@ -1249,6 +1251,9 @@
 	if (session->GetGUID() == server.m_HostGUID)
 		server.StartGame();
 
+	// Prevent player drops during game loading.
+	session->SetLongTimeout(true);
+
 	return true;
 }
 
@@ -1280,6 +1285,9 @@
 	loadedSession->SendMessage(&message);
 	server.Broadcast(&message, { NSS_INGAME });
 
+	// The client has loaded, so no longer needs a long timeout.
+	loadedSession->SetLongTimeout(false);
+
 	return true;
 }
 
@@ -1356,6 +1364,9 @@
 		session->SendMessage(&pausedMessage);
 	}
 
+	// The client has loaded, so no longer needs a long timeout to prevent drops.
+	session->SetLongTimeout(false);
+
 	return true;
 }
 
Index: source/network/NetSession.h
===================================================================
--- source/network/NetSession.h
+++ source/network/NetSession.h
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -105,6 +105,12 @@
 	 */
 	u32 GetMeanRTT() const;
 
+	/**
+	 * Allows increasing the timeout to prevent drops during an expensive operation,
+     * and decreasing it back to normal afterwards.
+	 */
+	void SetLongTimeout(bool longTimeout);
+
 	CNetFileTransferer& GetFileTransferer() { return m_FileTransferer; }
 
 private:
@@ -182,6 +188,12 @@
 	void SetLocalClient(bool isLocalClient);
 
 	/**
+	 * Allows increasing the timeout to prevent drops during an expensive operation,
+     * and decreasing it back to normal afterwards.
+	 */
+	void SetLongTimeout(bool longTimeout);
+
+	/**
 	 * Send a message to the client.
 	 */
 	virtual bool SendMessage(const CNetMessage* message);
Index: source/network/NetSession.cpp
===================================================================
--- source/network/NetSession.cpp
+++ source/network/NetSession.cpp
@@ -1,4 +1,4 @@
-/* Copyright (C) 2017 Wildfire Games.
+/* Copyright (C) 2018 Wildfire Games.
  * This file is part of 0 A.D.
  *
  * 0 A.D. is free software: you can redistribute it and/or modify
@@ -27,11 +27,21 @@
 #include "scriptinterface/ScriptInterface.h"
 
 const u32 NETWORK_WARNING_TIMEOUT = 2000;
-
+const u32 NETWORK_GAMESTART_TIMEOUT = 80000;
 const u32 MAXIMUM_HOST_TIMEOUT = std::numeric_limits<u32>::max();
 
 static const int CHANNEL_COUNT = 1;
 
+void LongTimeout(ENetPeer* peer, bool longTimeout)
+{
+#if (ENET_VERSION >= ENET_VERSION_CREATE(1, 3, 4))
+	if (longTimeout)
+		enet_peer_timeout(peer, 0, NETWORK_GAMESTART_TIMEOUT, NETWORK_GAMESTART_TIMEOUT);
+	else
+		enet_peer_timeout(peer, 0, 0, 0);
+#endif
+}
+
 CNetClientSession::CNetClientSession(CNetClient& client) :
 	m_Client(client), m_FileTransferer(this), m_Host(NULL), m_Server(NULL), m_Stats(NULL)
 {
@@ -200,7 +210,10 @@
 	return m_Server->roundTripTime;
 }
 
-
+void CNetClientSession::SetLongTimeout(bool longTimeout)
+{
+	LongTimeout(m_Server, longTimeout);
+}
 
 CNetServerSession::CNetServerSession(CNetServerWorker& server, ENetPeer* peer) :
 	m_Server(server), m_FileTransferer(this), m_Peer(peer)
@@ -262,3 +275,11 @@
 	enet_peer_timeout(m_Peer, 0, MAXIMUM_HOST_TIMEOUT, MAXIMUM_HOST_TIMEOUT);
 #endif
 }
+
+void CNetServerSession::SetLongTimeout(bool longTimeout)
+{
+	// Don't change the timeout if the client is local, since that is handled by SetLocalClient.
+	if (m_IsLocalClient)
+		return;
+	LongTimeout(m_Peer, longTimeout);
+}