diff --git a/src/main/java/org/telegram/api/Contact.java b/src/main/java/org/telegram/api/Contact.java
index 8d7d4a5..53b893b 100644
--- a/src/main/java/org/telegram/api/Contact.java
+++ b/src/main/java/org/telegram/api/Contact.java
@@ -22,7 +22,7 @@ public class Contact {
     private String lastName; ///< Optional. Contact's last name
     public static final String USERID_FIELD = "user_id";
     @JsonProperty(USERID_FIELD)
-    private String userID; ///< Optional. Contact's user identifier in Telegram
+    private Integer userID; ///< Optional. Contact's user identifier in Telegram
 
     public Contact() {
         super();
@@ -33,6 +33,6 @@ public class Contact {
         this.phoneNumber = jsonObject.getString(PHONENUMBER_FIELD);
         this.firstName = jsonObject.getString(FIRSTNAME_FIELD);
         this.lastName = jsonObject.optString(LASTNAME_FIELD, "");
-        this.userID = jsonObject.optString(USERID_FIELD, "");
+        this.userID = jsonObject.optInt(USERID_FIELD, 0);
     }
 }
diff --git a/src/main/java/org/telegram/api/Sticker.java b/src/main/java/org/telegram/api/Sticker.java
index 781794c..a5e756e 100644
--- a/src/main/java/org/telegram/api/Sticker.java
+++ b/src/main/java/org/telegram/api/Sticker.java
@@ -36,7 +36,11 @@ public class Sticker {
         this.fileId = jsonObject.getString(FILEID_FIELD);
         this.width = jsonObject.getInt(WIDTH_FIELD);
         this.height = jsonObject.getInt(HEIGHT_FIELD);
-        this.thumb = new PhotoSize(jsonObject.getJSONObject(THUMB_FIELD));
+        if (jsonObject.has(THUMB_FIELD)) {
+            this.thumb = new PhotoSize(jsonObject.getJSONObject(THUMB_FIELD));
+        } else {
+            this.thumb = null;
+        }
         this.fileSize = jsonObject.optInt(FILESIZE_FIELD, 0);
     }
 }
diff --git a/src/main/java/org/telegram/api/Video.java b/src/main/java/org/telegram/api/Video.java
index 5b826b0..a0a2607 100644
--- a/src/main/java/org/telegram/api/Video.java
+++ b/src/main/java/org/telegram/api/Video.java
@@ -32,9 +32,6 @@ public class Video {
     public static final String FILESIZE_FIELD = "file_size";
     @JsonProperty(FILESIZE_FIELD)
     private Integer fileSize; ///< Optional. File size
-    public static final String CAPTION_FIELD = "caption";
-    @JsonProperty(CAPTION_FIELD)
-    private String caption; ///< Optional. Text description of the video (usually empty)
 
     public Video() {
         super();
@@ -45,10 +42,13 @@ public class Video {
         this.width = jsonObject.getInt(WIDTH_FIELD);
         this.height = jsonObject.getInt(HEIGHT_FIELD);
         this.duration = jsonObject.getInt(DURATION_FIELD);
-        this.thumb = new PhotoSize(jsonObject.getJSONObject(THUMB_FIELD));
+        if (jsonObject.has(THUMB_FIELD)) {
+            this.thumb = new PhotoSize(jsonObject.getJSONObject(THUMB_FIELD));
+        } else {
+            this.thumb = null;
+        }
         this.mimeType = jsonObject.optString(MIMETYPE_FIELD, "");
         this.fileSize = jsonObject.optInt(FILESIZE_FIELD, 0);
-        this.caption = jsonObject.optString(CAPTION_FIELD, "");
     }
 
     public Integer getWidth() {
@@ -106,12 +106,4 @@ public class Video {
     public void setFileSize(Integer fileSize) {
         this.fileSize = fileSize;
     }
-
-    public String getCaption() {
-        return caption;
-    }
-
-    public void setCaption(String caption) {
-        this.caption = caption;
-    }
 }
diff --git a/src/main/java/org/telegram/methods/SendVideo.java b/src/main/java/org/telegram/methods/SendVideo.java
index 30c578d..7357a20 100644
--- a/src/main/java/org/telegram/methods/SendVideo.java
+++ b/src/main/java/org/telegram/methods/SendVideo.java
@@ -17,6 +17,10 @@ public class SendVideo {
     private Integer chatId; ///< Unique identifier for the message recepient — User or GroupChat id
     public static final String VIDEO_FIELD = "video";
     private String video; ///< Video to send. file_id as String to resend a video that is already on the Telegram servers
+    public static final String DURATION_FIELD = "duration";
+    private String duration; ///< Optional. Duration of sent video in seconds
+    public static final String CAPTION_FIELD = "caption";
+    private String caption; ///< OptionaL. Video caption (may also be used when resending videos by file_id).
     public static final String REPLYTOMESSAGEID_FIELD = "reply_to_message_id";
     private Integer replayToMessageId; ///< Optional. If the message is a reply, ID of the original message
     public static final String REPLYMARKUP_FIELD = "reply_markup";