diff --git a/lib/telegram/bot/types/background_fill_freeform_gradient.rb b/lib/telegram/bot/types/background_fill_freeform_gradient.rb
index 9ebef50..de2919f 100644
--- a/lib/telegram/bot/types/background_fill_freeform_gradient.rb
+++ b/lib/telegram/bot/types/background_fill_freeform_gradient.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundFillFreeformGradient < Base
-        attribute :type, Types::String.default('freeform_gradient')
+        attribute :type, Types::String.constrained(eql: 'freeform_gradient').default('freeform_gradient')
         attribute :colors, Types::Array.of(Types::Integer)
       end
     end
diff --git a/lib/telegram/bot/types/background_fill_gradient.rb b/lib/telegram/bot/types/background_fill_gradient.rb
index 79595ed..01ab0fe 100644
--- a/lib/telegram/bot/types/background_fill_gradient.rb
+++ b/lib/telegram/bot/types/background_fill_gradient.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundFillGradient < Base
-        attribute :type, Types::String.default('gradient')
+        attribute :type, Types::String.constrained(eql: 'gradient').default('gradient')
         attribute :top_color, Types::Integer
         attribute :bottom_color, Types::Integer
         attribute :rotation_angle, Types::Integer
diff --git a/lib/telegram/bot/types/background_fill_solid.rb b/lib/telegram/bot/types/background_fill_solid.rb
index 4c65523..5a14631 100644
--- a/lib/telegram/bot/types/background_fill_solid.rb
+++ b/lib/telegram/bot/types/background_fill_solid.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundFillSolid < Base
-        attribute :type, Types::String.default('solid')
+        attribute :type, Types::String.constrained(eql: 'solid').default('solid')
         attribute :color, Types::Integer
       end
     end
diff --git a/lib/telegram/bot/types/background_type_chat_theme.rb b/lib/telegram/bot/types/background_type_chat_theme.rb
index 612fef0..ca2051a 100644
--- a/lib/telegram/bot/types/background_type_chat_theme.rb
+++ b/lib/telegram/bot/types/background_type_chat_theme.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundTypeChatTheme < Base
-        attribute :type, Types::String.default('chat_theme')
+        attribute :type, Types::String.constrained(eql: 'chat_theme').default('chat_theme')
         attribute :theme_name, Types::String
       end
     end
diff --git a/lib/telegram/bot/types/background_type_fill.rb b/lib/telegram/bot/types/background_type_fill.rb
index 47aae7c..8c9e359 100644
--- a/lib/telegram/bot/types/background_type_fill.rb
+++ b/lib/telegram/bot/types/background_type_fill.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundTypeFill < Base
-        attribute :type, Types::String.default('fill')
+        attribute :type, Types::String.constrained(eql: 'fill').default('fill')
         attribute :fill, BackgroundFill
         attribute :dark_theme_dimming, Types::Integer
       end
diff --git a/lib/telegram/bot/types/background_type_pattern.rb b/lib/telegram/bot/types/background_type_pattern.rb
index 68e4c6e..b1801a7 100644
--- a/lib/telegram/bot/types/background_type_pattern.rb
+++ b/lib/telegram/bot/types/background_type_pattern.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundTypePattern < Base
-        attribute :type, Types::String.default('pattern')
+        attribute :type, Types::String.constrained(eql: 'pattern').default('pattern')
         attribute :document, Document
         attribute :fill, BackgroundFill
         attribute :intensity, Types::Integer
diff --git a/lib/telegram/bot/types/background_type_wallpaper.rb b/lib/telegram/bot/types/background_type_wallpaper.rb
index 0ead919..2827217 100644
--- a/lib/telegram/bot/types/background_type_wallpaper.rb
+++ b/lib/telegram/bot/types/background_type_wallpaper.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class BackgroundTypeWallpaper < Base
-        attribute :type, Types::String.default('wallpaper')
+        attribute :type, Types::String.constrained(eql: 'wallpaper').default('wallpaper')
         attribute :document, Document
         attribute :dark_theme_dimming, Types::Integer
         attribute? :is_blurred, Types::True
diff --git a/lib/telegram/bot/types/input_paid_media_photo.rb b/lib/telegram/bot/types/input_paid_media_photo.rb
index e791867..24bfdb4 100644
--- a/lib/telegram/bot/types/input_paid_media_photo.rb
+++ b/lib/telegram/bot/types/input_paid_media_photo.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class InputPaidMediaPhoto < Base
-        attribute :type, Types::String.default('photo')
+        attribute :type, Types::String.constrained(eql: 'photo').default('photo')
         attribute :media, Types::String
       end
     end
diff --git a/lib/telegram/bot/types/input_paid_media_video.rb b/lib/telegram/bot/types/input_paid_media_video.rb
index 3762775..bf50aaa 100644
--- a/lib/telegram/bot/types/input_paid_media_video.rb
+++ b/lib/telegram/bot/types/input_paid_media_video.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class InputPaidMediaVideo < Base
-        attribute :type, Types::String.default('video')
+        attribute :type, Types::String.constrained(eql: 'video').default('video')
         attribute :media, Types::String
         attribute? :thumbnail, Types::String
         attribute? :width, Types::Integer
diff --git a/lib/telegram/bot/types/paid_media_preview.rb b/lib/telegram/bot/types/paid_media_preview.rb
index 63d8e67..045bf73 100644
--- a/lib/telegram/bot/types/paid_media_preview.rb
+++ b/lib/telegram/bot/types/paid_media_preview.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class PaidMediaPreview < Base
-        attribute :type, Types::String.default('preview')
+        attribute :type, Types::String.constrained(eql: 'preview').default('preview')
         attribute? :width, Types::Integer
         attribute? :height, Types::Integer
         attribute? :duration, Types::Integer
diff --git a/lib/telegram/bot/types/paid_media_video.rb b/lib/telegram/bot/types/paid_media_video.rb
index a417679..564f3c0 100644
--- a/lib/telegram/bot/types/paid_media_video.rb
+++ b/lib/telegram/bot/types/paid_media_video.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class PaidMediaVideo < Base
-        attribute :type, Types::String.default('video')
+        attribute :type, Types::String.constrained(eql: 'video').default('video')
         attribute :video, Video
       end
     end
diff --git a/lib/telegram/bot/types/refunded_payment.rb b/lib/telegram/bot/types/refunded_payment.rb
index 7e3eff9..c33b248 100644
--- a/lib/telegram/bot/types/refunded_payment.rb
+++ b/lib/telegram/bot/types/refunded_payment.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class RefundedPayment < Base
-        attribute :currency, Types::String.default('XTR')
+        attribute :currency, Types::String.constrained(eql: 'XTR').default('XTR')
         attribute :total_amount, Types::Integer
         attribute :invoice_payload, Types::String
         attribute :telegram_payment_charge_id, Types::String
diff --git a/lib/telegram/bot/types/transaction_partner_fragment.rb b/lib/telegram/bot/types/transaction_partner_fragment.rb
index c597d80..029a3d8 100644
--- a/lib/telegram/bot/types/transaction_partner_fragment.rb
+++ b/lib/telegram/bot/types/transaction_partner_fragment.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class TransactionPartnerFragment < Base
-        attribute :type, Types::String.default('fragment')
+        attribute :type, Types::String.constrained(eql: 'fragment').default('fragment')
         attribute? :withdrawal_state, RevenueWithdrawalState
       end
     end
diff --git a/lib/telegram/bot/types/transaction_partner_other.rb b/lib/telegram/bot/types/transaction_partner_other.rb
index 40c5f83..f7dfc12 100644
--- a/lib/telegram/bot/types/transaction_partner_other.rb
+++ b/lib/telegram/bot/types/transaction_partner_other.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class TransactionPartnerOther < Base
-        attribute :type, Types::String.default('other')
+        attribute :type, Types::String.constrained(eql: 'other').default('other')
       end
     end
   end
diff --git a/lib/telegram/bot/types/transaction_partner_telegram_ads.rb b/lib/telegram/bot/types/transaction_partner_telegram_ads.rb
index 3f5bdaf..955039d 100644
--- a/lib/telegram/bot/types/transaction_partner_telegram_ads.rb
+++ b/lib/telegram/bot/types/transaction_partner_telegram_ads.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class TransactionPartnerTelegramAds < Base
-        attribute :type, Types::String.default('telegram_ads')
+        attribute :type, Types::String.constrained(eql: 'telegram_ads').default('telegram_ads')
       end
     end
   end
diff --git a/lib/telegram/bot/types/transaction_partner_user.rb b/lib/telegram/bot/types/transaction_partner_user.rb
index 77b16e0..0759ce3 100644
--- a/lib/telegram/bot/types/transaction_partner_user.rb
+++ b/lib/telegram/bot/types/transaction_partner_user.rb
@@ -4,7 +4,7 @@ module Telegram
   module Bot
     module Types
       class TransactionPartnerUser < Base
-        attribute :type, Types::String.default('user')
+        attribute :type, Types::String.constrained(eql: 'user').default('user')
         attribute :user, User
         attribute? :invoice_payload, Types::String
         attribute? :paid_media, Types::Array