diff --git a/src/client/voice/VoiceConnection.js b/src/client/voice/VoiceConnection.js
index 1a5a43e901a1..8c1057fc3742 100644
--- a/src/client/voice/VoiceConnection.js
+++ b/src/client/voice/VoiceConnection.js
@@ -165,7 +165,7 @@ class VoiceConnection extends EventEmitter {
 
   /**
    * The voice state of this connection
-   * @type {VoiceState}
+   * @type {?VoiceState}
    */
   get voice() {
     return this.channel.guild.voice;
@@ -203,8 +203,8 @@ class VoiceConnection extends EventEmitter {
    * Set the token and endpoint required to connect to the voice servers.
    * @param {string} token The voice token
    * @param {string} endpoint The voice endpoint
-   * @private
    * @returns {void}
+   * @private
    */
   setTokenAndEndpoint(token, endpoint) {
     this.emit('debug', `Token "${token}" and endpoint "${endpoint}"`);
diff --git a/src/client/voice/dispatcher/StreamDispatcher.js b/src/client/voice/dispatcher/StreamDispatcher.js
index 62c46d37e25c..bb1c7bbad537 100644
--- a/src/client/voice/dispatcher/StreamDispatcher.js
+++ b/src/client/voice/dispatcher/StreamDispatcher.js
@@ -56,7 +56,7 @@ class StreamDispatcher extends Writable {
      * The broadcast controlling this dispatcher, if any
      * @type {?VoiceBroadcast}
      */
-    this.broadcast = this.streams.broadcast;
+    this.broadcast = this.streams.broadcast || null;
 
     this._pausedTime = 0;
     this._silentPausedTime = 0;
diff --git a/src/client/websocket/WebSocketManager.js b/src/client/websocket/WebSocketManager.js
index e75ca7931fc5..f892985fa9d1 100644
--- a/src/client/websocket/WebSocketManager.js
+++ b/src/client/websocket/WebSocketManager.js
@@ -43,7 +43,7 @@ class WebSocketManager extends EventEmitter {
      * The gateway this manager uses
      * @type {?string}
      */
-    this.gateway = undefined;
+    this.gateway = null;
 
     /**
      * The amount of shards this manager handles
@@ -98,11 +98,11 @@ class WebSocketManager extends EventEmitter {
      * The current session limit of the client
      * @private
      * @type {?Object}
-     * @prop {number} total Total number of identifies available
-     * @prop {number} remaining Number of identifies remaining
-     * @prop {number} reset_after Number of milliseconds after which the limit resets
+     * @property {number} total Total number of identifies available
+     * @property {number} remaining Number of identifies remaining
+     * @property {number} reset_after Number of milliseconds after which the limit resets
      */
-    this.sessionStartLimit = undefined;
+    this.sessionStartLimit = null;
   }
 
   /**
@@ -212,7 +212,7 @@ class WebSocketManager extends EventEmitter {
 
         if (UNRESUMABLE_CLOSE_CODES.includes(event.code)) {
           // These event codes cannot be resumed
-          shard.sessionID = undefined;
+          shard.sessionID = null;
         }
 
         /**
diff --git a/src/client/websocket/WebSocketShard.js b/src/client/websocket/WebSocketShard.js
index 2da290a5ce9d..f99c83f8fbf0 100644
--- a/src/client/websocket/WebSocketShard.js
+++ b/src/client/websocket/WebSocketShard.js
@@ -56,10 +56,10 @@ class WebSocketShard extends EventEmitter {
 
     /**
      * The current session ID of the shard
-     * @type {string}
+     * @type {?string}
      * @private
      */
-    this.sessionID = undefined;
+    this.sessionID = null;
 
     /**
      * The previous heartbeat ping of the shard
@@ -124,7 +124,7 @@ class WebSocketShard extends EventEmitter {
      * @type {?NodeJS.Timeout}
      * @private
      */
-    Object.defineProperty(this, 'helloTimeout', { value: undefined, writable: true });
+    Object.defineProperty(this, 'helloTimeout', { value: null, writable: true });
 
     /**
      * If the manager attached its event handlers on the shard
@@ -140,7 +140,7 @@ class WebSocketShard extends EventEmitter {
      * @type {?Set<string>}
      * @private
      */
-    Object.defineProperty(this, 'expectedGuilds', { value: undefined, writable: true });
+    Object.defineProperty(this, 'expectedGuilds', { value: null, writable: true });
 
     /**
      * The ready timeout
@@ -148,7 +148,7 @@ class WebSocketShard extends EventEmitter {
      * @type {?NodeJS.Timeout}
      * @private
      */
-    Object.defineProperty(this, 'readyTimeout', { value: undefined, writable: true });
+    Object.defineProperty(this, 'readyTimeout', { value: null, writable: true });
 
     /**
      * Time when the WebSocket connection was opened
@@ -428,7 +428,7 @@ class WebSocketShard extends EventEmitter {
         // Reset the sequence
         this.sequence = -1;
         // Reset the session ID as it's invalid
-        this.sessionID = undefined;
+        this.sessionID = null;
         // Set the status to reconnecting
         this.status = Status.RECONNECTING;
         // Finally, emit the INVALID_SESSION event
@@ -457,7 +457,7 @@ class WebSocketShard extends EventEmitter {
     // Step 0. Clear the ready timeout, if it exists
     if (this.readyTimeout) {
       this.manager.client.clearTimeout(this.readyTimeout);
-      this.readyTimeout = undefined;
+      this.readyTimeout = null;
     }
     // Step 1. If we don't have any other guilds pending, we are ready
     if (!this.expectedGuilds.size) {
@@ -480,7 +480,7 @@ class WebSocketShard extends EventEmitter {
       this.debug(`Shard did not receive any more guild packets in 15 seconds.
   Unavailable guild count: ${this.expectedGuilds.size}`);
 
-      this.readyTimeout = undefined;
+      this.readyTimeout = null;
 
       this.status = Status.READY;
 
@@ -498,7 +498,7 @@ class WebSocketShard extends EventEmitter {
       if (this.helloTimeout) {
         this.debug('Clearing the HELLO timeout.');
         this.manager.client.clearTimeout(this.helloTimeout);
-        this.helloTimeout = undefined;
+        this.helloTimeout = null;
       }
       return;
     }
@@ -519,7 +519,7 @@ class WebSocketShard extends EventEmitter {
       if (this.heartbeatInterval) {
         this.debug('Clearing the heartbeat interval.');
         this.manager.client.clearInterval(this.heartbeatInterval);
-        this.heartbeatInterval = undefined;
+        this.heartbeatInterval = null;
       }
       return;
     }
@@ -734,7 +734,7 @@ class WebSocketShard extends EventEmitter {
     // Step 5: Reset the sequence and session ID if requested
     if (reset) {
       this.sequence = -1;
-      this.sessionID = undefined;
+      this.sessionID = null;
     }
 
     // Step 6: reset the ratelimit data
diff --git a/src/sharding/Shard.js b/src/sharding/Shard.js
index 797dde50fbcb..75b17c83d49b 100644
--- a/src/sharding/Shard.js
+++ b/src/sharding/Shard.js
@@ -44,7 +44,7 @@ class Shard extends EventEmitter {
 
     /**
      * Arguments for the shard's process executable (only when {@link ShardingManager#mode} is `process`)
-     * @type {?string[]}
+     * @type {string[]}
      */
     this.execArgv = manager.execArgv;
 
@@ -96,7 +96,7 @@ class Shard extends EventEmitter {
      * @type {Function}
      * @private
      */
-    this._exitListener = this._handleExit.bind(this, undefined);
+    this._exitListener = this._handleExit.bind(this);
   }
 
   /**
diff --git a/src/sharding/ShardClientUtil.js b/src/sharding/ShardClientUtil.js
index 79345d889917..292a033d047e 100644
--- a/src/sharding/ShardClientUtil.js
+++ b/src/sharding/ShardClientUtil.js
@@ -125,7 +125,7 @@ class ShardClientUtil {
   }
 
   /**
-   * Evaluates a script or function on all shards, in the context of the {@link Clients}.
+   * Evaluates a script or function on all shards, in the context of the {@link Client}s.
    * @param {string|Function} script JavaScript to run on each shard
    * @returns {Promise<Array<*>>} Results of the script execution
    * @example
diff --git a/src/structures/Base.js b/src/structures/Base.js
index 65c1fa5e1e19..cd43bf799e34 100644
--- a/src/structures/Base.js
+++ b/src/structures/Base.js
@@ -4,6 +4,7 @@ const Util = require('../util/Util');
 
 /**
  * Represents a data model that is identifiable by a Snowflake (i.e. Discord API data models).
+ * @abstract
  */
 class Base {
   constructor(client) {
diff --git a/src/structures/BaseGuildEmoji.js b/src/structures/BaseGuildEmoji.js
index 3dc9819f3e6b..a2007c677b8f 100644
--- a/src/structures/BaseGuildEmoji.js
+++ b/src/structures/BaseGuildEmoji.js
@@ -5,6 +5,7 @@ const Emoji = require('./Emoji');
 /**
  * Parent class for {@link GuildEmoji} and {@link GuildPreviewEmoji}.
  * @extends {Emoji}
+ * @abstract
  */
 class BaseGuildEmoji extends Emoji {
   constructor(client, data, guild) {
@@ -16,6 +17,10 @@ class BaseGuildEmoji extends Emoji {
      */
     this.guild = guild;
 
+    this.requireColons = null;
+    this.managed = null;
+    this.available = null;
+
     /**
      * Array of role ids this emoji is active for
      * @name BaseGuildEmoji#_roles
@@ -30,26 +35,29 @@ class BaseGuildEmoji extends Emoji {
   _patch(data) {
     if (data.name) this.name = data.name;
 
-    /**
-     * Whether or not this emoji requires colons surrounding it
-     * @type {?boolean}
-     * @name GuildEmoji#requiresColons
-     */
-    if (typeof data.require_colons !== 'undefined') this.requiresColons = data.require_colons;
+    if (typeof data.require_colons !== 'undefined') {
+      /**
+       * Whether or not this emoji requires colons surrounding it
+       * @type {?boolean}
+       */
+      this.requiresColons = data.require_colons;
+    }
 
-    /**
-     * Whether this emoji is managed by an external service
-     * @type {?boolean}
-     * @name GuildEmoji#managed
-     */
-    if (typeof data.managed !== 'undefined') this.managed = data.managed;
+    if (typeof data.managed !== 'undefined') {
+      /**
+       * Whether this emoji is managed by an external service
+       * @type {?boolean}
+       */
+      this.managed = data.managed;
+    }
 
-    /**
-     * Whether this emoji is available
-     * @type {?boolean}
-     * @name GuildEmoji#available
-     */
-    if (typeof data.available !== 'undefined') this.available = data.available;
+    if (typeof data.available !== 'undefined') {
+      /**
+       * Whether this emoji is available
+       * @type {?boolean}
+       */
+      this.available = data.available;
+    }
 
     if (data.roles) this._roles = data.roles;
   }
diff --git a/src/structures/Channel.js b/src/structures/Channel.js
index 52867c645f05..baa02ee64edb 100644
--- a/src/structures/Channel.js
+++ b/src/structures/Channel.js
@@ -7,6 +7,7 @@ const Snowflake = require('../util/Snowflake');
 /**
  * Represents any channel on Discord.
  * @extends {Base}
+ * @abstract
  */
 class Channel extends Base {
   constructor(client, data) {
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index 558e57c28a5c..664aad238db3 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -231,36 +231,38 @@ class Guild extends Base {
      */
     this.premiumTier = data.premium_tier;
 
-    /**
-     * The total number of boosts for this server
-     * @type {?number}
-     * @name Guild#premiumSubscriptionCount
-     */
     if (typeof data.premium_subscription_count !== 'undefined') {
+      /**
+       * The total number of boosts for this server
+       * @type {?number}
+       */
       this.premiumSubscriptionCount = data.premium_subscription_count;
     }
 
-    /**
-     * Whether widget images are enabled on this guild
-     * @type {?boolean}
-     * @name Guild#widgetEnabled
-     */
-    if (typeof data.widget_enabled !== 'undefined') this.widgetEnabled = data.widget_enabled;
+    if (typeof data.widget_enabled !== 'undefined') {
+      /**
+       * Whether widget images are enabled on this guild
+       * @type {?boolean}
+       */
+      this.widgetEnabled = data.widget_enabled;
+    }
 
-    /**
-     * The widget channel ID, if enabled
-     * @type {?string}
-     * @name Guild#widgetChannelID
-     */
-    if (typeof data.widget_channel_id !== 'undefined') this.widgetChannelID = data.widget_channel_id;
+    if (typeof data.widget_channel_id !== 'undefined') {
+      /**
+       * The widget channel ID, if enabled
+       * @type {?string}
+       */
+      this.widgetChannelID = data.widget_channel_id;
+    }
 
-    /**
-     * The embed channel ID, if enabled
-     * @type {?string}
-     * @name Guild#embedChannelID
-     * @deprecated
-     */
-    if (typeof data.embed_channel_id !== 'undefined') this.embedChannelID = data.embed_channel_id;
+    if (typeof data.embed_channel_id !== 'undefined') {
+      /**
+       * The embed channel ID, if enabled
+       * @type {?string}
+       * @deprecated
+       */
+      this.embedChannelID = data.embed_channel_id;
+    }
 
     /**
      * The verification level of the guild
@@ -299,40 +301,47 @@ class Guild extends Base {
      */
     this.systemChannelFlags = new SystemChannelFlags(data.system_channel_flags).freeze();
 
-    /**
-     * The maximum amount of members the guild can have
-     * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
-     * @type {?number}
-     * @name Guild#maximumMembers
-     */
-    if (typeof data.max_members !== 'undefined') this.maximumMembers = data.max_members || 250000;
+    if (typeof data.max_members !== 'undefined') {
+      /**
+       * The maximum amount of members the guild can have
+       * @type {?number}
+       */
+      this.maximumMembers = data.max_members;
+    } else if (typeof this.maximumMembers === 'undefined') {
+      this.maximumMembers = null;
+    }
 
-    /**
-     * The maximum amount of presences the guild can have
-     * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
-     * @type {?number}
-     * @name Guild#maximumPresences
-     */
-    if (typeof data.max_presences !== 'undefined') this.maximumPresences = data.max_presences || 25000;
+    if (typeof data.max_presences !== 'undefined') {
+      /**
+       * The maximum amount of presences the guild can have
+       * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
+       * @type {?number}
+       */
+      this.maximumPresences = data.max_presences || 25000;
+    } else if (typeof this.maximumPresences === 'undefined') {
+      this.maximumPresences = null;
+    }
 
-    /**
-     * The approximate amount of members the guild has
-     * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
-     * @type {?number}
-     * @name Guild#approximateMemberCount
-     */
     if (typeof data.approximate_member_count !== 'undefined') {
+      /**
+       * The approximate amount of members the guild has
+       * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
+       * @type {?number}
+       */
       this.approximateMemberCount = data.approximate_member_count;
+    } else if (typeof this.approximateMemberCount === 'undefined') {
+      this.approximateMemberCount = null;
     }
 
-    /**
-     * The approximate amount of presences the guild has
-     * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
-     * @type {?number}
-     * @name Guild#approximatePresenceCount
-     */
     if (typeof data.approximate_presence_count !== 'undefined') {
+      /**
+       * The approximate amount of presences the guild has
+       * <info>You will need to fetch the guild using {@link Guild#fetch} if you want to receive this parameter</info>
+       * @type {?number}
+       */
       this.approximatePresenceCount = data.approximate_presence_count;
+    } else if (typeof this.approximatePresenceCount === 'undefined') {
+      this.approximatePresenceCount = null;
     }
 
     /**
diff --git a/src/structures/GuildAuditLogs.js b/src/structures/GuildAuditLogs.js
index b3522b055858..823b0037ac03 100644
--- a/src/structures/GuildAuditLogs.js
+++ b/src/structures/GuildAuditLogs.js
@@ -24,7 +24,7 @@ const Util = require('../util/Util');
 /**
  * Key mirror of all available audit log targets.
  * @name GuildAuditLogs.Targets
- * @type {AuditLogTargetType}
+ * @type {Object<string, string>}
  */
 const Targets = {
   ALL: 'ALL',
@@ -84,7 +84,7 @@ const Targets = {
 /**
  * All available actions keyed under their names to their numeric values.
  * @name GuildAuditLogs.Actions
- * @type {AuditLogAction}
+ * @type {Object<string, number>}
  */
 const Actions = {
   ALL: null,
diff --git a/src/structures/GuildChannel.js b/src/structures/GuildChannel.js
index 573ad09911db..b4347e6104c5 100644
--- a/src/structures/GuildChannel.js
+++ b/src/structures/GuildChannel.js
@@ -17,6 +17,7 @@ const Util = require('../util/Util');
  * - {@link NewsChannel}
  * - {@link StoreChannel}
  * @extends {Channel}
+ * @abstract
  */
 class GuildChannel extends Channel {
   /**
@@ -31,6 +32,8 @@ class GuildChannel extends Channel {
      * @type {Guild}
      */
     this.guild = guild;
+
+    this.parentID = null;
   }
 
   _patch(data) {
@@ -298,7 +301,7 @@ class GuildChannel extends Channel {
    * @property {boolean} [nsfw] Whether the channel is NSFW
    * @property {number} [bitrate] The bitrate of the voice channel
    * @property {number} [userLimit] The user limit of the voice channel
-   * @property {Snowflake} [parentID] The parent ID of the channel
+   * @property {?Snowflake} [parentID] The parent ID of the channel
    * @property {boolean} [lockPermissions]
    * Lock the permissions of the channel to what the parent's permissions are
    * @property {OverwriteResolvable[]|Collection<Snowflake, OverwriteResolvable>} [permissionOverwrites]
diff --git a/src/structures/GuildMember.js b/src/structures/GuildMember.js
index 05ca569e6fae..1bd0dfd1dc09 100644
--- a/src/structures/GuildMember.js
+++ b/src/structures/GuildMember.js
@@ -61,7 +61,6 @@ class GuildMember extends Base {
     /**
      * The nickname of this member, if they have one
      * @type {?string}
-     * @name GuildMember#nickname
      */
     this.nickname = null;
 
@@ -74,7 +73,6 @@ class GuildMember extends Base {
       /**
        * The user that this guild member instance represents
        * @type {User}
-       * @name GuildMember#user
        */
       this.user = this.client.users.add(data.user, true);
     }
diff --git a/src/structures/GuildPreview.js b/src/structures/GuildPreview.js
index c2175d4e714a..76f53424f9df 100644
--- a/src/structures/GuildPreview.js
+++ b/src/structures/GuildPreview.js
@@ -75,7 +75,7 @@ class GuildPreview extends Base {
      * The description for this guild
      * @type {?string}
      */
-    this.description = data.description;
+    this.description = data.description || null;
 
     if (!this.emojis) {
       /**
diff --git a/src/structures/Integration.js b/src/structures/Integration.js
index 1c7a0d411574..a48019a61b3f 100644
--- a/src/structures/Integration.js
+++ b/src/structures/Integration.js
@@ -65,6 +65,8 @@ class Integration extends Base {
        * @type {?User}
        */
       this.user = this.client.users.add(data.user);
+    } else {
+      this.user = null;
     }
 
     /**
diff --git a/src/structures/MessageEmbed.js b/src/structures/MessageEmbed.js
index b9319ed1db1d..ef007a551cec 100644
--- a/src/structures/MessageEmbed.js
+++ b/src/structures/MessageEmbed.js
@@ -29,37 +29,37 @@ class MessageEmbed {
      * * `link` - a link embed
      * @type {string}
      */
-    this.type = data.type;
+    this.type = data.type || 'rich';
 
     /**
      * The title of this embed
      * @type {?string}
      */
-    this.title = data.title;
+    this.title = 'title' in data ? data.title : null;
 
     /**
      * The description of this embed
      * @type {?string}
      */
-    this.description = data.description;
+    this.description = 'description' in data ? data.description : null;
 
     /**
      * The URL of this embed
      * @type {?string}
      */
-    this.url = data.url;
+    this.url = 'url' in data ? data.url : null;
 
     /**
      * The color of this embed
      * @type {?number}
      */
-    this.color = Util.resolveColor(data.color);
+    this.color = 'color' in data ? Util.resolveColor(data.color) : null;
 
     /**
      * The timestamp of this embed
      * @type {?number}
      */
-    this.timestamp = data.timestamp ? new Date(data.timestamp).getTime() : null;
+    this.timestamp = 'timestamp' in data ? new Date(data.timestamp).getTime() : null;
 
     /**
      * Represents a field of a MessageEmbed
@@ -331,7 +331,7 @@ class MessageEmbed {
    */
   setFooter(text, iconURL) {
     text = Util.resolveString(text);
-    this.footer = { text, iconURL, proxyIconURL: undefined };
+    this.footer = { text, iconURL };
     return this;
   }
 
diff --git a/src/structures/MessageReaction.js b/src/structures/MessageReaction.js
index 771626edad30..ac0e04dc4644 100644
--- a/src/structures/MessageReaction.js
+++ b/src/structures/MessageReaction.js
@@ -46,13 +46,14 @@ class MessageReaction {
   }
 
   _patch(data) {
-    /**
-     * The number of people that have given the same reaction
-     * @type {?number}
-     * @name MessageReaction#count
-     */
     // eslint-disable-next-line eqeqeq
-    if (this.count == undefined) this.count = data.count;
+    if (this.count == undefined) {
+      /**
+       * The number of people that have given the same reaction
+       * @type {?number}
+       */
+      this.count = data.count;
+    }
   }
 
   /**
diff --git a/src/structures/Presence.js b/src/structures/Presence.js
index ac07a5432052..2ae6b8c0d99f 100644
--- a/src/structures/Presence.js
+++ b/src/structures/Presence.js
@@ -184,8 +184,8 @@ class Activity {
     /**
      * Timestamps for the activity
      * @type {?Object}
-     * @prop {?Date} start When the activity started
-     * @prop {?Date} end When the activity will end
+     * @property {?Date} start When the activity started
+     * @property {?Date} end When the activity will end
      */
     this.timestamps = data.timestamps
       ? {
@@ -197,8 +197,8 @@ class Activity {
     /**
      * Party of the activity
      * @type {?Object}
-     * @prop {?string} id ID of the party
-     * @prop {number[]} size Size of the party as `[current, max]`
+     * @property {?string} id ID of the party
+     * @property {number[]} size Size of the party as `[current, max]`
      */
     this.party = data.party || null;
 
diff --git a/src/structures/User.js b/src/structures/User.js
index bcc73016b4dd..f99bf6d15b37 100644
--- a/src/structures/User.js
+++ b/src/structures/User.js
@@ -27,6 +27,10 @@ class User extends Base {
      */
     this.id = data.id;
 
+    this.system = null;
+    this.locale = null;
+    this.flags = null;
+
     this._patch(data);
   }
 
@@ -35,7 +39,6 @@ class User extends Base {
       /**
        * The username of the user
        * @type {?string}
-       * @name User#username
        */
       this.username = data.username;
     } else if (typeof this.username !== 'string') {
@@ -45,7 +48,6 @@ class User extends Base {
     /**
      * Whether or not the user is a bot
      * @type {boolean}
-     * @name User#bot
      */
     this.bot = Boolean(data.bot);
 
@@ -53,7 +55,6 @@ class User extends Base {
       /**
        * A discriminator based on username for the user
        * @type {?string}
-       * @name User#discriminator
        */
       this.discriminator = data.discriminator;
     } else if (typeof this.discriminator !== 'string') {
@@ -64,7 +65,6 @@ class User extends Base {
       /**
        * The ID of the user's avatar
        * @type {?string}
-       * @name User#avatar
        */
       this.avatar = data.avatar;
     } else if (typeof this.avatar !== 'string') {
@@ -75,7 +75,6 @@ class User extends Base {
       /**
        * Whether the user is an Official Discord System user (part of the urgent message system)
        * @type {?boolean}
-       * @name User#system
        */
       this.system = Boolean(data.system);
     }
@@ -84,7 +83,6 @@ class User extends Base {
       /**
        * The locale of the user's client (ISO 639-1)
        * @type {?string}
-       * @name User#locale
        */
       this.locale = data.locale;
     }
@@ -93,7 +91,6 @@ class User extends Base {
       /**
        * The flags for this user
        * @type {?UserFlags}
-       * @name User#flags
        */
       this.flags = new UserFlags(data.public_flags);
     }
diff --git a/src/structures/VoiceChannel.js b/src/structures/VoiceChannel.js
index 6fb5ab78bd8d..2b9eb9e15c35 100644
--- a/src/structures/VoiceChannel.js
+++ b/src/structures/VoiceChannel.js
@@ -29,7 +29,6 @@ class VoiceChannel extends GuildChannel {
   /**
    * The members in this voice channel
    * @type {Collection<Snowflake, GuildMember>}
-   * @name VoiceChannel#members
    * @readonly
    */
   get members() {
diff --git a/src/structures/VoiceState.js b/src/structures/VoiceState.js
index 2854d94dbfc9..731c7ef45427 100644
--- a/src/structures/VoiceState.js
+++ b/src/structures/VoiceState.js
@@ -32,32 +32,32 @@ class VoiceState extends Base {
      * Whether this member is deafened server-wide
      * @type {?boolean}
      */
-    this.serverDeaf = data.deaf;
+    this.serverDeaf = 'deaf' in data ? data.deaf : null;
     /**
      * Whether this member is muted server-wide
      * @type {?boolean}
      */
-    this.serverMute = data.mute;
+    this.serverMute = 'mute' in data ? data.mute : null;
     /**
      * Whether this member is self-deafened
      * @type {?boolean}
      */
-    this.selfDeaf = data.self_deaf;
+    this.selfDeaf = 'self_deaf' in data ? data.self_deaf : null;
     /**
      * Whether this member is self-muted
      * @type {?boolean}
      */
-    this.selfMute = data.self_mute;
+    this.selfMute = 'self_mute' in data ? data.self_mute : null;
     /**
      * Whether this member's camera is enabled
-     * @type {boolean}
+     * @type {?boolean}
      */
-    this.selfVideo = data.self_video;
+    this.selfVideo = 'self_video' in data ? data.self_video : null;
     /**
      * The session ID of this member's connection
      * @type {?string}
      */
-    this.sessionID = data.session_id;
+    this.sessionID = 'session_id' in data ? data.session_id : null;
     /**
      * Whether this member is streaming using "Go Live"
      * @type {boolean}
@@ -67,7 +67,7 @@ class VoiceState extends Base {
      * The ID of the voice channel that this member is in
      * @type {?Snowflake}
      */
-    this.channelID = data.channel_id;
+    this.channelID = data.channel_id || null;
     return this;
   }
 
diff --git a/typings/index.d.ts b/typings/index.d.ts
index fd21dc033172..041039f9c884 100644
--- a/typings/index.d.ts
+++ b/typings/index.d.ts
@@ -142,13 +142,13 @@ declare module 'discord.js' {
     constructor(client: Client, data: object, guild: Guild);
     private _roles: string[];
 
-    public available?: boolean;
+    public available: boolean | null;
     public readonly createdAt: Date;
     public readonly createdTimestamp: number;
     public guild: Guild | GuildPreview;
     public id: Snowflake;
-    public managed?: boolean;
-    public requiresColons?: boolean;
+    public managed: boolean | null;
+    public requiresColons: boolean | null;
   }
 
   class BroadcastDispatcher extends VolumeMixin(StreamDispatcher) {
@@ -625,8 +625,8 @@ declare module 'discord.js' {
     public afkChannelID: Snowflake | null;
     public afkTimeout: number;
     public applicationID: Snowflake | null;
-    public approximateMemberCount?: number;
-    public approximatePresenceCount?: number;
+    public approximateMemberCount: number | null;
+    public approximatePresenceCount: number | null;
     public available: boolean;
     public banner: string | null;
     public channels: GuildChannelManager;
@@ -818,7 +818,7 @@ declare module 'discord.js' {
     public permissionsFor(memberOrRole: GuildMemberResolvable | RoleResolvable): Readonly<Permissions> | null;
     public setName(name: string, reason?: string): Promise<this>;
     public setParent(
-      channel: CategoryChannel | Snowflake,
+      channel: CategoryChannel | Snowflake | null,
       options?: { lockPermissions?: boolean; reason?: string },
     ): Promise<this>;
     public setPosition(position: number, options?: { relative?: boolean; reason?: string }): Promise<this>;
@@ -932,7 +932,7 @@ declare module 'discord.js' {
     public syncedAt: number;
     public syncing: boolean;
     public type: string;
-    public user?: User;
+    public user: User | null;
     public delete(reason?: string): Promise<Integration>;
     public edit(data: IntegrationEditData, reason?: string): Promise<Integration>;
     public sync(): Promise<Integration>;
@@ -1054,7 +1054,7 @@ declare module 'discord.js' {
     public attachment: BufferResolvable | Stream;
     public height: number | null;
     public id: Snowflake;
-    public name?: string;
+    public name: string | null;
     public proxyURL: string;
     public size: number;
     public readonly spoiler: boolean;
@@ -1082,9 +1082,9 @@ declare module 'discord.js' {
   export class MessageEmbed {
     constructor(data?: MessageEmbed | MessageEmbedOptions);
     public author: MessageEmbedAuthor | null;
-    public color?: number;
+    public color: number | null;
     public readonly createdAt: Date | null;
-    public description?: string;
+    public description: string | null;
     public fields: EmbedField[];
     public files: (MessageAttachment | string | FileOptions)[];
     public footer: MessageEmbedFooter | null;
@@ -1094,9 +1094,9 @@ declare module 'discord.js' {
     public provider: MessageEmbedProvider | null;
     public thumbnail: MessageEmbedThumbnail | null;
     public timestamp: number | null;
-    public title?: string;
+    public title: string | null;
     public type: string;
-    public url?: string;
+    public url: string | null;
     public readonly video: MessageEmbedVideo | null;
     public addField(name: StringResolvable, value: StringResolvable, inline?: boolean): this;
     public addFields(...fields: EmbedFieldData[] | EmbedFieldData[][]): this;
@@ -1540,13 +1540,13 @@ declare module 'discord.js' {
     public discriminator: string;
     public readonly defaultAvatarURL: string;
     public readonly dmChannel: DMChannel | null;
-    public flags?: Readonly<UserFlags>;
+    public flags: Readonly<UserFlags> | null;
     public id: Snowflake;
     public lastMessageID: Snowflake | null;
-    public locale?: string;
+    public locale: string | null;
     public readonly partial: false;
     public readonly presence: Presence;
-    public system?: boolean;
+    public system: boolean | null;
     public readonly tag: string;
     public username: string;
     public avatarURL(options?: ImageURLOptions & { dynamic?: boolean }): string | null;
@@ -1613,7 +1613,7 @@ declare module 'discord.js' {
     constructor(client: Client);
     public client: Client;
     public subscribers: StreamDispatcher[];
-    public readonly dispatcher?: BroadcastDispatcher;
+    public readonly dispatcher: BroadcastDispatcher | null;
     public play(input: string | Readable, options?: StreamOptions): BroadcastDispatcher;
     public end(): void;
 
@@ -1669,7 +1669,7 @@ declare module 'discord.js' {
     public receiver: VoiceReceiver;
     public speaking: Readonly<Speaking>;
     public status: VoiceStatus;
-    public readonly voice: VoiceState;
+    public readonly voice: VoiceState | null;
     public voiceManager: ClientVoiceManager;
     public disconnect(): void;
     public play(input: VoiceBroadcast | Readable | string, options?: StreamOptions): StreamDispatcher;
@@ -1721,18 +1721,18 @@ declare module 'discord.js' {
   export class VoiceState extends Base {
     constructor(guild: Guild, data: object);
     public readonly channel: VoiceChannel | null;
-    public channelID?: Snowflake;
+    public channelID: Snowflake | null;
     public readonly connection: VoiceConnection | null;
-    public readonly deaf?: boolean;
+    public readonly deaf: boolean | null;
     public guild: Guild;
     public id: Snowflake;
     public readonly member: GuildMember | null;
-    public readonly mute?: boolean;
-    public selfDeaf?: boolean;
-    public selfMute?: boolean;
-    public serverDeaf?: boolean;
-    public serverMute?: boolean;
-    public sessionID?: string;
+    public readonly mute: boolean | null;
+    public selfDeaf: boolean | null;
+    public selfMute: boolean | null;
+    public serverDeaf: boolean | null;
+    public serverMute: boolean | null;
+    public sessionID: string | null;
     public streaming: boolean;
     public selfVideo: boolean;
     public readonly speaking: boolean | null;
@@ -1786,10 +1786,10 @@ declare module 'discord.js' {
     private packetQueue: object[];
     private destroyed: boolean;
     private reconnecting: boolean;
-    private sessionStartLimit?: { total: number; remaining: number; reset_after: number };
+    private sessionStartLimit: { total: number; remaining: number; reset_after: number } | null;
 
     public readonly client: Client;
-    public gateway?: string;
+    public gateway: string | null;
     public shards: Collection<number, WebSocketShard>;
     public status: Status;
     public readonly ping: number;
@@ -1813,15 +1813,15 @@ declare module 'discord.js' {
     constructor(manager: WebSocketManager, id: number);
     private sequence: number;
     private closeSequence: number;
-    private sessionID?: string;
+    private sessionID: string | null;
     private lastPingTimestamp: number;
     private lastHeartbeatAcked: boolean;
     private ratelimit: { queue: object[]; total: number; remaining: number; time: 60e3; timer: NodeJS.Timeout | null };
     private connection: WebSocket | null;
-    private helloTimeout: NodeJS.Timeout | undefined;
+    private helloTimeout: NodeJS.Timeout | null;
     private eventsAttached: boolean;
-    private expectedGuilds: Set<Snowflake> | undefined;
-    private readyTimeout: NodeJS.Timeout | undefined;
+    private expectedGuilds: Set<Snowflake> | null;
+    private readyTimeout: NodeJS.Timeout | null;
 
     public manager: WebSocketManager;
     public id: number;
@@ -2234,7 +2234,7 @@ declare module 'discord.js' {
     nsfw?: boolean;
     bitrate?: number;
     userLimit?: number;
-    parentID?: Snowflake;
+    parentID?: Snowflake | null;
     rateLimitPerUser?: number;
     lockPermissions?: boolean;
     permissionOverwrites?: readonly OverwriteResolvable[] | Collection<Snowflake, OverwriteResolvable>;