diff --git a/src/network/clientopcodes.h b/src/network/clientopcodes.h
index 683d3534d..20bfc6697 100644
--- a/src/network/clientopcodes.h
+++ b/src/network/clientopcodes.h
@@ -20,10 +20,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
+#include "client/client.h"
 #include "networkprotocol.h"
 
 class NetworkPacket;
-class Client;
+// Note: don't forward-declare Client here (#14324)
 
 enum ToClientConnectionState {
 	TOCLIENT_STATE_NOT_CONNECTED,
diff --git a/src/network/serveropcodes.h b/src/network/serveropcodes.h
index c461da44a..275270ab9 100644
--- a/src/network/serveropcodes.h
+++ b/src/network/serveropcodes.h
@@ -20,10 +20,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 
 #pragma once
 
+#include "server.h"
 #include "networkprotocol.h"
 
 class NetworkPacket;
-class Server;
+// Note: don't forward-declare Server here (#14324)
 
 enum ToServerConnectionState {
 	TOSERVER_STATE_NOT_CONNECTED,