diff --git a/src/client/component/config.cpp b/src/client/component/config.cpp
index afd3686e..96d56631 100644
--- a/src/client/component/config.cpp
+++ b/src/client/component/config.cpp
@@ -3,6 +3,7 @@
 
 #include "config.hpp"
 #include "console.hpp"
+#include "language.hpp"
 
 #include <utils/hook.hpp>
 #include <utils/io.hpp>
@@ -11,6 +12,55 @@
 
 namespace config
 {
+	namespace
+	{
+		using validate_type_callback_t = std::function<bool(const field_value&)>;
+		using validate_callback_t = std::function<bool(const field_value&)>;
+
+		struct field_definition_t
+		{
+			field_type type;
+			field_value default_value;
+			std::optional<validate_callback_t> validate_value = {};
+		};
+
+		template <typename... Args>
+		std::pair<std::string, field_definition_t> define_field(const std::string& name, Args&&... args)
+		{
+			return std::make_pair(name, field_definition_t{std::forward<Args>(args)...});
+		}
+
+		std::unordered_map<std::string, field_definition_t> field_definitions =
+		{
+			{define_field("language", config::field_type::string, language::get_default_language(), language::is_valid_language)},
+		};
+	}
+	
+	nlohmann::json validate_config_field(const std::string& key, const nlohmann::json& value)
+	{
+		const auto iter = field_definitions.find(key);
+		if (iter == field_definitions.end())
+		{
+			return value;
+		}
+
+		if (value.type() != iter->second.type)
+		{
+			return iter->second.default_value;
+		}
+
+		if (iter->second.validate_value.has_value())
+		{
+			const auto& validate_value = iter->second.validate_value.value();
+			if (!validate_value(value))
+			{
+				iter->second.default_value;
+			}
+		}
+
+		return value;
+	}
+
 	void write_config(const nlohmann::json& json)
 	{
 		try
diff --git a/src/client/component/config.hpp b/src/client/component/config.hpp
index 91395404..0066050b 100644
--- a/src/client/component/config.hpp
+++ b/src/client/component/config.hpp
@@ -2,9 +2,14 @@
 
 namespace config
 {
+	typedef nlohmann::json::value_t field_type;
+	typedef nlohmann::json field_value;
+
 	nlohmann::json read_config();
 	void write_config(const nlohmann::json& json);
 
+	nlohmann::json validate_config_field(const std::string& key, const field_value& value);
+
 	template <typename T>
 	std::optional<T> get(const std::string& key)
 	{
@@ -14,14 +19,15 @@ namespace config
 			return {};
 		}
 
-		return {cfg[key].get<T>()};
+		const auto value = validate_config_field(key, cfg[key]);
+		return {value.get<T>()};
 	}
 
 	template <typename T>
 	void set(const std::string& key, const T& value)
 	{
 		auto cfg = read_config();
-		cfg[key] = value;
+		cfg[key] = validate_config_field(key, value);
 		write_config(cfg);
 	}
 }
diff --git a/src/client/component/database.cpp b/src/client/component/database.cpp
index bcf44034..5bcadb97 100644
--- a/src/client/component/database.cpp
+++ b/src/client/component/database.cpp
@@ -7,6 +7,7 @@
 #include "filesystem.hpp"
 #include "console.hpp"
 #include "command.hpp"
+#include "language.hpp"
 
 #include <utils/io.hpp>
 #include <utils/hook.hpp>
@@ -116,25 +117,6 @@ namespace database
 			return file.ends_with(".ff") || file.ends_with(".pak");
 		}
 
-		std::unordered_set<game::language_t> unsuppored_languages =
-		{
-			{game::LANGUAGE_CZECH}
-		};
-
-		bool is_unsupported_language(const std::string& name)
-		{
-			for (auto i = 0; i < 17; i++)
-			{
-				if ((game::languages[i].name == name || game::languages[i].shortname == name) && 
-					unsuppored_languages.contains(static_cast<game::language_t>(i)))
-				{
-					return true;
-				}
-			}
-
-			return false;
-		}
-
 		bool is_loc_folder(game::Sys_Folder folder)
 		{
 			return folder == game::SF_PAKFILE_LOC || folder == game::SF_ZONE_LOC || folder == game::SF_VIDEO_LOC;
@@ -160,7 +142,7 @@ namespace database
 				{
 					const auto loc = name.substr(0, 3);
 					const auto found = find_fastfile(name);
-					if (is_unsupported_language(loc) && !found.has_value())
+					if (language::is_custom_language(loc) && !found.has_value())
 					{
 						name = "eng" + name.substr(3);
 						file_ = name;
@@ -421,7 +403,7 @@ namespace database
 		utils::hook::detour sys_set_folder_hook;
 		void sys_set_folder_stub(game::Sys_Folder folder, const char* path)
 		{
-			if (is_loc_folder(folder) && is_unsupported_language(path))
+			if (is_loc_folder(folder) && language::is_custom_language(path))
 			{
 				path = "english";
 			}
diff --git a/src/client/component/language.cpp b/src/client/component/language.cpp
index e00bc099..09e01060 100644
--- a/src/client/component/language.cpp
+++ b/src/client/component/language.cpp
@@ -8,6 +8,9 @@
 
 #include <utils/hook.hpp>
 #include <utils/io.hpp>
+#include <utils/string.hpp>
+
+#define OLD_LANGUAGE_FILE "players2/default/language"
 
 namespace language
 {
@@ -27,20 +30,25 @@ namespace language
 			{game::LANGUAGE_RUSSIAN_PARTIAL},
 		};
 
-		std::unordered_set<game::language_t> cyrillic_languages =
+		std::unordered_set<game::language_t> polish_russian_languages =
 		{
-			game::LANGUAGE_RUSSIAN,
-			game::LANGUAGE_POLISH,
-			game::LANGUAGE_CZECH,
-			game::LANGUAGE_RUSSIAN_PARTIAL,
+			{game::LANGUAGE_RUSSIAN},
+			{game::LANGUAGE_POLISH},
+			{game::LANGUAGE_CZECH},
+			{game::LANGUAGE_RUSSIAN_PARTIAL},
 		};
 
 		std::unordered_set<game::language_t> asian_languages =
 		{
-			game::LANGUAGE_JAPANESE_FULL,
-			game::LANGUAGE_JAPANESE_PARTIAL,
-			game::LANGUAGE_TRADITIONAL_CHINESE,
-			game::LANGUAGE_SIMPLIFIED_CHINESE,
+			{game::LANGUAGE_JAPANESE_FULL},
+			{game::LANGUAGE_JAPANESE_PARTIAL},
+			{game::LANGUAGE_TRADITIONAL_CHINESE},
+			{game::LANGUAGE_SIMPLIFIED_CHINESE},
+		};
+
+		std::unordered_set<game::language_t> custom_languages =
+		{
+			{game::LANGUAGE_CZECH},
 		};
 
 		const char* get_loc_language_string()
@@ -58,6 +66,40 @@ namespace language
 		}
 	}
 
+	std::string get_default_language()
+	{
+		return "english";
+	}
+
+	bool is_valid_language(const std::string& name)
+	{
+		const auto lower = utils::string::to_lower(name);
+		for (auto i = 0; i < game::LANGUAGE_COUNT; i++)
+		{
+			const auto a = game::languages[i].name;
+			const auto b = game::languages[i].is_supported;
+			if (game::languages[i].name == lower)
+			{
+				return true;
+			}
+		}
+
+		return false;
+	}
+
+	bool is_custom_language(const std::string& name)
+	{
+		for (const auto& language : custom_languages)
+		{
+			if (game::languages[language].name == name || game::languages[language].shortname == name)
+			{
+				return true;
+			}
+		}
+
+		return false;
+	}
+
 	game::language_t current()
 	{
 		static auto* loc_language = game::Dvar_FindVar("loc_language");
@@ -71,7 +113,7 @@ namespace language
 
 	bool is_polrus()
 	{
-		return cyrillic_languages.contains(current());
+		return polish_russian_languages.contains(current());
 	}
 
 	bool is_arabic()
@@ -91,7 +133,7 @@ namespace language
 
 	void set_from_index(const int index)
 	{
-		if (index < 0 || index > 17)
+		if (index < 0 || index >= game::LANGUAGE_COUNT)
 		{
 			return;
 		}
@@ -107,9 +149,16 @@ namespace language
 		{
 			utils::hook::call(0x14060AFFB, get_loc_language_string);
 
-			for (auto i = 0; i < 17; i++)
+			if (utils::io::file_exists(OLD_LANGUAGE_FILE))
 			{
-				game::languages[i].is_supported = 1;
+				const auto lang = utils::io::read_file(OLD_LANGUAGE_FILE);
+				config::set("language", lang);
+				utils::io::remove_file(OLD_LANGUAGE_FILE);
+			}
+
+			for (const auto& language : custom_languages)
+			{
+				game::languages[language].is_supported = 1;
 			}
 		}
 	};
diff --git a/src/client/component/language.hpp b/src/client/component/language.hpp
index e1a54eea..a549951a 100644
--- a/src/client/component/language.hpp
+++ b/src/client/component/language.hpp
@@ -4,6 +4,10 @@
 
 namespace language
 {
+	std::string get_default_language();
+	bool is_valid_language(const std::string& name);
+	bool is_custom_language(const std::string& name);
+
 	void set(const std::string& language);
 	void set_from_index(const int index);