diff --git a/src/core/types/chat.rs b/src/core/types/chat.rs
index d808668f..1382d6a8 100644
--- a/src/core/types/chat.rs
+++ b/src/core/types/chat.rs
@@ -1,33 +1,83 @@
 use crate::core::types::{ChatPermissions, ChatPhoto, Message};
 
-#[derive(Debug, Deserialize, Eq, Hash, PartialEq)]
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
 pub struct Chat {
+    #[serde(rename = "chat_id")]
     pub id: i32,
     #[serde(flatten)]
     pub type_: ChatType,
+    #[serde(skip_serializing_if = "Option::is_none")]
     pub photo: Option<ChatPhoto>,
 }
 
-#[derive(Debug, Deserialize, Eq, Hash, PartialEq)]
+struct PrivateChatTypeVisitor;
+
+impl<'de> serde::de::Visitor<'de> for PrivateChatTypeVisitor {
+    type Value = ();
+
+    fn expecting(&self, f: &mut std::fmt::Formatter) -> std::fmt::Result {
+        write!(f, r#"field equal to "private""#)
+    }
+
+    fn visit_borrowed_str<E: serde::de::Error>(
+        self,
+        v: &'de str,
+    ) -> Result<Self::Value, E> {
+        match v {
+            "private" => Ok(()),
+            _ => Err(E::invalid_value(
+                serde::de::Unexpected::Str(v),
+                &r#""private""#,
+            )),
+        }
+    }
+}
+
+fn assert_private_field<'de, D: serde::Deserializer<'de>>(
+    des: D,
+) -> Result<(), D::Error> {
+    des.deserialize_str(PrivateChatTypeVisitor)
+}
+
+fn serialize_private_field<S: serde::Serializer>(
+    _: &(),
+    ser: S,
+) -> Result<S::Ok, S::Error> {
+    ser.serialize_str("private")
+}
+
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
 #[serde(rename_all = "snake_case")]
 #[serde(untagged)]
 pub enum ChatType {
     NotPrivate {
+        #[serde(skip_serializing_if = "Option::is_none")]
         title: Option<String>,
         #[serde(flatten)]
         type_: NotPrivateChatType,
+        #[serde(skip_serializing_if = "Option::is_none")]
         description: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
         invite_link: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
         pinned_message: Option<Box<Message>>,
     },
     Private {
+        /// Dummy field. Used to ensure that "type" field is equal to "private"
+        #[serde(rename = "type")]
+        #[serde(deserialize_with = "assert_private_field")]
+        #[serde(serialize_with = "serialize_private_field")]
+        type_: (),
+        #[serde(skip_serializing_if = "Option::is_none")]
         username: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
         first_name: Option<String>,
+        #[serde(skip_serializing_if = "Option::is_none")]
         last_name: Option<String>,
     },
 }
 
-#[derive(Debug, Deserialize, Eq, Hash, PartialEq)]
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
 #[serde(rename_all = "snake_case")]
 #[serde(tag = "type")]
 pub enum NotPrivateChatType {
@@ -45,25 +95,72 @@ pub enum NotPrivateChatType {
     },
 }
 
-#[test]
-fn test_chat_de() {
-    use serde_json::from_str;
+#[cfg(test)]
+mod tests {
+    use crate::core::types::*;
+    use serde_json::{from_str, to_string};
 
-    assert_eq!(
-        Chat {
-            id: 0,
-            type_: ChatType::NotPrivate {
-                title: None,
-                type_: NotPrivateChatType::Channel {
-                    username: Some("channelname".into())
+    #[test]
+    fn channel_de() {
+        assert_eq!(
+            Chat {
+                id: -1,
+                type_: ChatType::NotPrivate {
+                    title: None,
+                    type_: NotPrivateChatType::Channel {
+                        username: Some("channelname".into())
+                    },
+                    description: None,
+                    invite_link: None,
+                    pinned_message: None
                 },
-                description: None,
-                invite_link: None,
-                pinned_message: None,
+                photo: None,
             },
-            photo: None,
-        },
-        from_str(r#"{"id":0,"type":"channel","username":"channelname"}"#)
+            from_str(
+                r#"{"chat_id":-1,"type":"channel","username":"channelname"}"#
+            )
             .unwrap()
-    );
+        );
+    }
+
+    #[test]
+    fn private_chat_de() {
+        assert_eq!(
+            Chat {
+                id: 0,
+                type_: ChatType::Private {
+                    type_: (),
+                    username: Some("username".into()),
+                    first_name: Some("Anon".into()),
+                    last_name: None
+                },
+                photo: None
+            },
+            from_str(
+                r#"{"chat_id":0,"type":"private","username":"username","first_name":"Anon"}"#
+            ).unwrap());
+    }
+
+    #[test]
+    fn private_chat_de_wrong_type_field() {
+        assert!(from_str::<Chat>(r#"{"chat_id":0,"type":"WRONG"}"#).is_err());
+    }
+
+    #[test]
+    fn private_chat_ser() {
+        assert_eq!(
+            to_string(&Chat {
+                id: 0,
+                type_: ChatType::Private {
+                    type_: (),
+                    username: None,
+                    first_name: None,
+                    last_name: None
+                },
+                photo: None
+            })
+            .unwrap(),
+            r#"{"chat_id":0,"type":"private"}"#.to_owned()
+        );
+    }
 }
diff --git a/src/core/types/chat_permissions.rs b/src/core/types/chat_permissions.rs
index 5e59cfc4..a6cb0d88 100644
--- a/src/core/types/chat_permissions.rs
+++ b/src/core/types/chat_permissions.rs
@@ -1,4 +1,4 @@
-#[derive(Debug, Deserialize, Hash, PartialEq, Eq)]
+#[derive(Debug, Deserialize, Hash, PartialEq, Eq, Serialize)]
 pub struct ChatPermissions {
     pub can_send_messages: Option<bool>,
     pub can_send_media_messages: Option<bool>,
diff --git a/src/core/types/chat_photo.rs b/src/core/types/chat_photo.rs
index 463284c7..edabbf33 100644
--- a/src/core/types/chat_photo.rs
+++ b/src/core/types/chat_photo.rs
@@ -1,4 +1,4 @@
-#[derive(Debug, Deserialize, Hash, PartialEq, Eq)]
+#[derive(Debug, Deserialize, Hash, PartialEq, Eq, Serialize)]
 pub struct ChatPhoto {
     pub small_file_id: String,
     pub big_file_id: String,
diff --git a/src/core/types/message.rs b/src/core/types/message.rs
index 112883fa..636693e1 100644
--- a/src/core/types/message.rs
+++ b/src/core/types/message.rs
@@ -4,53 +4,17 @@ use crate::core::types::{
     SuccessfulPayment, User, Venue, Video, VideoNote, Voice,
 };
 
-#[derive(Debug, Deserialize, Eq, Hash, PartialEq)]
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
 pub struct Message {
-    pub message_id: i64,
-    pub from: Option<Box<User>>,
-    pub date: i64,
+    #[serde(rename = "message_id")]
+    pub id: i32,
+    pub date: i32,
     pub chat: Chat,
-    pub forward_from: Option<User>,
-    pub forward_from_chat: Option<Chat>,
-    pub forward_from_message_id: Option<i64>,
-    pub forward_signature: Option<String>,
-    pub forward_sender_name: Option<String>,
-    pub forward_date: Option<i64>,
-    pub reply_to_message: Option<Box<Message>>,
-    pub edit_date: Option<i64>,
-    pub media_group_id: Option<String>,
-    pub author_signature: Option<String>,
-    pub text: Option<String>,
-    pub entities: Option<Vec<MessageEntity>>,
-    pub caption_entities: Option<Vec<MessageEntity>>,
-    pub audio: Option<Audio>,
-    pub document: Option<Document>,
-    pub animation: Option<Animation>,
-    pub game: Option<Game>,
-    pub photo: Option<Vec<PhotoSize>>,
-    pub sticker: Option<Sticker>,
-    pub video: Option<Video>,
-    pub voice: Option<Voice>,
-    pub video_note: Option<VideoNote>,
-    pub caption: Option<String>,
-    pub contact: Option<Contact>,
-    pub location: Option<Location>,
-    pub venue: Option<Venue>,
-    pub poll: Option<Poll>,
-    pub new_chat_members: Option<Vec<User>>,
-    pub left_chat_member: Option<User>,
-    pub new_chat_title: Option<String>,
-    pub new_chat_photo: Option<Vec<PhotoSize>>,
-    pub delete_chat_photo: Option<bool>,
-    pub group_chat_created: Option<bool>,
-    pub supergroup_chat_created: Option<bool>,
-    pub channel_chat_created: Option<bool>,
-    pub migrate_to_chat_id: Option<i64>,
-    pub migrate_from_chat_id: Option<i64>,
-    pub pinned_message: Option<Box<Message>>,
-    pub invoice: Option<Invoice>,
-    pub successful_payment: Option<SuccessfulPayment>,
-    pub connected_website: Option<String>,
-    pub passport_data: Option<PassportData>,
-    pub reply_markup: Option<InlineKeyboardMarkup>,
+    #[serde(flatten)]
+    pub type_: MessageType,
 }
+
+#[derive(Debug, Deserialize, Eq, Hash, PartialEq, Serialize)]
+#[serde(rename_all = "snake_case")]
+#[serde(untagged)]
+pub enum MessageType {}
diff --git a/src/core/types/mod.rs b/src/core/types/mod.rs
index 11e39b53..33fdbbde 100644
--- a/src/core/types/mod.rs
+++ b/src/core/types/mod.rs
@@ -1,16 +1,31 @@
 use self::not_implemented_types::*;
 pub use self::{
     answer_pre_checkout_query::AnswerPreCheckoutQuery,
-    answer_shipping_query::AnswerShippingQuery, audio::Audio, chat::Chat,
-    chat_member::ChatMember, chat_permissions::ChatPermissions,
-    chat_photo::ChatPhoto, document::Document, input_file::InputFile,
-    input_media::InputMedia, invoice::Invoice, label_price::LabeledPrice,
-    message::Message, message_entity::MessageEntity, order_info::OrderInfo,
-    parse_mode::ParseMode, photo_size::PhotoSize,
-    pre_checkout_query::PreCheckoutQuery, send_invoice::SendInvoice,
-    shipping_address::ShippingAddress, shipping_option::ShippingOption,
-    shipping_query::ShippingQuery, sticker::Sticker,
-    successful_payment::SuccessfulPayment, user::User, video::Video,
+    answer_shipping_query::AnswerShippingQuery,
+    audio::Audio,
+    chat::{Chat, ChatType, NotPrivateChatType},
+    chat_member::ChatMember,
+    chat_permissions::ChatPermissions,
+    chat_photo::ChatPhoto,
+    document::Document,
+    input_file::InputFile,
+    input_media::InputMedia,
+    invoice::Invoice,
+    label_price::LabeledPrice,
+    message::Message,
+    message_entity::MessageEntity,
+    order_info::OrderInfo,
+    parse_mode::ParseMode,
+    photo_size::PhotoSize,
+    pre_checkout_query::PreCheckoutQuery,
+    send_invoice::SendInvoice,
+    shipping_address::ShippingAddress,
+    shipping_option::ShippingOption,
+    shipping_query::ShippingQuery,
+    sticker::Sticker,
+    successful_payment::SuccessfulPayment,
+    user::User,
+    video::Video,
 };
 
 mod answer_pre_checkout_query;
diff --git a/src/core/types/response_paramter.rs b/src/core/types/response_parameter.rs
similarity index 100%
rename from src/core/types/response_paramter.rs
rename to src/core/types/response_parameter.rs