diff --git a/Examples/Program_DownloadSavedMedia.cs b/Examples/Program_DownloadSavedMedia.cs
index f6e088c..d1004b9 100644
--- a/Examples/Program_DownloadSavedMedia.cs
+++ b/Examples/Program_DownloadSavedMedia.cs
@@ -21,7 +21,7 @@ namespace WTelegramClientTest
 
 			async void Client_Update(IObject arg)
 			{
-				if (arg is not Updates { updates: var updates }) return;
+				if (arg is not Updates { updates: var updates } upd) return;
 				foreach (var update in updates)
 				{
 					if (update is not UpdateNewMessage { message: Message message })
diff --git a/src/Client.cs b/src/Client.cs
index e84cae9..5877014 100644
--- a/src/Client.cs
+++ b/src/Client.cs
@@ -98,11 +98,12 @@ namespace WTelegram
 			_dcSession = dcSession;
 		}
 
-		internal string Config(string config)
-			=> _config(config) ?? DefaultConfig(config) ?? throw new ApplicationException("You must provide a config value for " + config);
+		internal Task<string> ConfigAsync(string what) => Task.Run(() => Config(what));
+		internal string Config(string what)
+			=> _config(what) ?? DefaultConfig(what) ?? throw new ApplicationException("You must provide a config value for " + what);
 
 		/// <summary>Default config values, used if your Config callback returns <see langword="null"/></summary>
-		public static string DefaultConfig(string config) => config switch
+		public static string DefaultConfig(string what) => what switch
 		{
 			"session_pathname" => Path.Combine(
 				Path.GetDirectoryName(Path.GetDirectoryName(AppDomain.CurrentDomain.BaseDirectory.TrimEnd(Path.DirectorySeparatorChar))),
@@ -119,7 +120,7 @@ namespace WTelegram
 			"lang_pack" => "",
 			"lang_code" => CultureInfo.CurrentUICulture.TwoLetterISOLanguageName,
 			"user_id" => "-1",
-			"verification_code" or "password" => AskConfig(config),
+			"verification_code" or "password" => AskConfig(what),
 			_ => null // api_id api_hash phone_number... it's up to you to reply to these correctly
 		};
 
@@ -1013,13 +1014,13 @@ namespace WTelegram
 			for (int retry = 1; authorization == null; retry++)
 				try
 				{
-					var verification_code = Config("verification_code");
+					var verification_code = await ConfigAsync("verification_code");
 					authorization = await this.Auth_SignIn(phone_number, sentCode.phone_code_hash, verification_code);
 				}
 				catch (RpcException e) when (e.Code == 401 && e.Message == "SESSION_PASSWORD_NEEDED")
 				{
 					var accountPassword = await this.Account_GetPassword();
-					var checkPasswordSRP = Check2FA(accountPassword, () => Config("password"));
+					var checkPasswordSRP = await Check2FA(accountPassword, () => ConfigAsync("password"));
 					authorization = await this.Auth_CheckPassword(checkPasswordSRP);
 				}
 				catch (RpcException e) when (e.Code == 400 && e.Message == "PHONE_CODE_INVALID" && retry != 3)
diff --git a/src/Encryption.cs b/src/Encryption.cs
index e32557f..9fa9c69 100644
--- a/src/Encryption.cs
+++ b/src/Encryption.cs
@@ -362,7 +362,7 @@ j4WcDuXc2CTHgH8gFTNhp/Y8/SpDOhvn9QIDAQAB
 			return output;
 		}
 
-		internal static InputCheckPasswordSRP Check2FA(Account_Password accountPassword, Func<string> getPassword)
+		internal static async Task<InputCheckPasswordSRP> Check2FA(Account_Password accountPassword, Func<Task<string>> getPassword)
 		{
 			if (accountPassword.current_algo is not PasswordKdfAlgoSHA256SHA256PBKDF2HMACSHA512iter100000SHA256ModPow algo)
 				throw new ApplicationException("2FA authentication uses an unsupported algo: " + accountPassword.current_algo?.GetType().Name);
@@ -376,7 +376,7 @@ j4WcDuXc2CTHgH8gFTNhp/Y8/SpDOhvn9QIDAQAB
 
 			System.Threading.Thread.Sleep(100);
 			Helpers.Log(3, $"This account has enabled 2FA. A password is needed. {accountPassword.hint}");
-			var passwordBytes = Encoding.UTF8.GetBytes(getPassword());
+			var passwordBytes = Encoding.UTF8.GetBytes(await getPassword());
 
 			using var sha256 = SHA256.Create();
 			sha256.TransformBlock(algo.salt1, 0, algo.salt1.Length, null, 0);
@@ -436,7 +436,7 @@ j4WcDuXc2CTHgH8gFTNhp/Y8/SpDOhvn9QIDAQAB
 			sha256.TransformFinalBlock(k_a, 0, 32);
 			var m1 = sha256.Hash;
 
-			validTask.Wait();
+			await validTask;
 			return new InputCheckPasswordSRP { A = g_a_256, M1 = m1, srp_id = accountPassword.srp_id };
 		}