diff --git a/src/network/network.h b/src/network/network.h
--- a/src/network/network.h
+++ b/src/network/network.h
@@ -76,12 +76,38 @@ enum NetworkJoinStatus {
 	NETWORK_JOIN_STATUS_GETTING_COMPANY_INFO,
 };
 
-// language ids for server_lang and client_lang
+/* Language ids for server_lang and client_lang. Do NOT modify the order. */
 enum NetworkLanguage {
-	NETLANG_ANY     = 0,
-	NETLANG_ENGLISH = 1,
-	NETLANG_GERMAN  = 2,
-	NETLANG_FRENCH  = 3,
+	NETLANG_ANY = 0,
+	NETLANG_ENGLISH,
+	NETLANG_GERMAN,
+	NETLANG_FRENCH,
+	NETLANG_BRAZILIAN,
+	NETLANG_BULGARIAN,
+	NETLANG_CHINESE,
+	NETLANG_CZECH,
+	NETLANG_DANISH,
+	NETLANG_DUTCH,
+	NETLANG_ESPERANTO,
+	NETLANG_FINNISH,
+	NETLANG_HUNGARIAN,
+	NETLANG_ICELANDIC,
+	NETLANG_ITALIAN,
+	NETLANG_JAPANESE,
+	NETLANG_KOREAN,
+	NETLANG_LITHUANIAN,
+	NETLANG_NORWEGIAN,
+	NETLANG_POLISH,
+	NETLANG_PORTUGUESE,
+	NETLANG_ROMANIAN,
+	NETLANG_RUSSIAN,
+	NETLANG_SLOVAK,
+	NETLANG_SLOVENIAN,
+	NETLANG_SPANISH,
+	NETLANG_SWEDISH,
+	NETLANG_TURKISH,
+	NETLANG_UKRAINIAN,
+	NETLANG_LAST
 };
 
 VARDEF NetworkGameInfo _network_game_info;