diff --git a/src/client/Client.js b/src/client/Client.js
index 6026a0d33..89d94f00f 100644
--- a/src/client/Client.js
+++ b/src/client/Client.js
@@ -406,7 +406,7 @@ class Client extends EventEmitter {
   /**
    * Generates a link that can be used to invite the bot to a guild.
    * <warn>This is only available when using a bot account.</warn>
-   * @param {PermissionResolvable|PermissionResolvable[]} [permissions] Permissions to request
+   * @param {PermissionResolvable} [permissions] Permissions to request
    * @returns {Promise<string>}
    * @example
    * client.generateInvite(['SEND_MESSAGES', 'MANAGE_GUILD', 'MENTION_EVERYONE'])
diff --git a/src/client/rest/RESTMethods.js b/src/client/rest/RESTMethods.js
index a826cd3b0..1dd054b9b 100644
--- a/src/client/rest/RESTMethods.js
+++ b/src/client/rest/RESTMethods.js
@@ -5,6 +5,7 @@ const Constants = require('../../util/Constants');
 const Endpoints = Constants.Endpoints;
 const Collection = require('../../util/Collection');
 const Util = require('../../util/Util');
+const resolvePermissions = require('../../structures/shared/resolvePermissions');
 
 const User = require('../../structures/User');
 const GuildMember = require('../../structures/GuildMember');
@@ -251,34 +252,10 @@ class RESTMethods {
   }
 
   createChannel(guild, channelName, channelType, overwrites, reason) {
-    if (overwrites instanceof Collection || overwrites instanceof Array) {
-      overwrites = overwrites.map(overwrite => {
-        let allow = overwrite.allow || overwrite._allowed;
-        let deny = overwrite.deny || overwrite._denied;
-        if (allow instanceof Array) allow = Permissions.resolve(allow);
-        if (deny instanceof Array) deny = Permissions.resolve(deny);
-
-        const role = this.client.resolver.resolveRole(guild, overwrite.id);
-        if (role) {
-          overwrite.id = role.id;
-          overwrite.type = 'role';
-        } else {
-          overwrite.id = this.client.resolver.resolveUserID(overwrite.id);
-          overwrite.type = 'member';
-        }
-
-        return {
-          allow,
-          deny,
-          type: overwrite.type,
-          id: overwrite.id,
-        };
-      });
-    }
     return this.rest.makeRequest('post', Endpoints.Guild(guild).channels, true, {
       name: channelName,
       type: channelType ? Constants.ChannelTypes[channelType.toUpperCase()] : 'text',
-      permission_overwrites: overwrites,
+      permission_overwrites: resolvePermissions.call(this, overwrites, guild),
     }, undefined, reason).then(data => this.client.actions.ChannelCreate.handle(data).channel);
   }
 
@@ -343,6 +320,8 @@ class RESTMethods {
     data.bitrate = _data.bitrate || (channel.bitrate ? channel.bitrate * 1000 : undefined);
     data.user_limit = typeof _data.userLimit !== 'undefined' ? _data.userLimit : channel.userLimit;
     data.parent_id = _data.parent;
+    data.permission_overwrites = _data.permissionOverwrites ?
+      resolvePermissions.call(this, _data.permissionOverwrites, channel.guild) : undefined;
     return this.rest.makeRequest('patch', Endpoints.Channel(channel), true, data, undefined, reason).then(newData =>
       this.client.actions.ChannelUpdate.handle(newData).updated
     );
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index 0150d6483..572175f91 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -969,8 +969,8 @@ class Guild {
   /**
    * Can be used to overwrite permissions when creating a channel.
    * @typedef {Object} ChannelCreationOverwrites
-   * @property {PermissionResolvable[]|number} [allow] The permissions to allow
-   * @property {PermissionResolvable[]|number} [deny] The permissions to deny
+   * @property {PermissionResolvable|number} [allow] The permissions to allow
+   * @property {PermissionResolvable|number} [deny] The permissions to deny
    * @property {RoleResolvable|UserResolvable} id ID of the role or member this overwrite is for
    */
 
diff --git a/src/structures/GuildChannel.js b/src/structures/GuildChannel.js
index 099854f01..0a7901f3a 100644
--- a/src/structures/GuildChannel.js
+++ b/src/structures/GuildChannel.js
@@ -140,6 +140,28 @@ class GuildChannel extends Channel {
     };
   }
 
+  /**
+   * Replaces the permission overwrites for a channel
+   * @param {Object} [options] Options
+   * @param {Array<PermissionOverwrites|PermissionOverwriteOptions>} [options.overwrites] Permission overwrites
+   * @param {string} [options.reason] Reason for updating the channel overwrites
+   * @returns {Promise<GuildChannel>}
+   * @example
+   * channel.replacePermissionOverwrites({
+   * overwrites: [
+   *   {
+   *      id: message.author.id,
+   *      denied: ['VIEW_CHANNEL'],
+   *   },
+   * ],
+   *   reason: 'Needed to change permissions'
+   * });
+   */
+  replacePermissionOverwrites({ overwrites, reason } = {}) {
+    return this.edit({ permissionOverwrites: overwrites, reason })
+      .then(() => this);
+  }
+
   /**
    * An object mapping permission flags to `true` (enabled), `false` (disabled), or `null` (not set).
    * ```js
@@ -215,6 +237,21 @@ class GuildChannel extends Channel {
     return this.client.rest.methods.setChannelOverwrite(this, payload, reason).then(() => this);
   }
 
+  /**
+   * Locks in the permission overwrites from the parent channel.
+   * @returns {Promise<GuildChannel>}
+   */
+  lockPermissions() {
+    if (!this.parent) return Promise.reject(new TypeError('Could not find a parent to this guild channel.'));
+    const permissionOverwrites = this.parent.permissionOverwrites.map(overwrite => ({
+      deny: overwrite.deny.bitfield,
+      allow: overwrite.allow.bitfield,
+      id: overwrite.id,
+      type: overwrite.type,
+    }));
+    return this.edit({ permissionOverwrites });
+  }
+
   /**
    * The data for a guild channel.
    * @typedef {Object} ChannelData
diff --git a/src/structures/GuildMember.js b/src/structures/GuildMember.js
index 1a56868ba..98d879769 100644
--- a/src/structures/GuildMember.js
+++ b/src/structures/GuildMember.js
@@ -305,7 +305,7 @@ class GuildMember {
 
   /**
    * Checks if any of this member's roles have a permission.
-   * @param {PermissionResolvable|PermissionResolvable[]} permission Permission(s) to check for
+   * @param {PermissionResolvable} permission Permission(s) to check for
    * @param {boolean} [explicit=false] Whether to require the role to explicitly have the exact permission
    * **(deprecated)**
    * @param {boolean} [checkAdmin] Whether to allow the administrator permission to override
@@ -323,7 +323,7 @@ class GuildMember {
 
   /**
    * Checks whether the roles of this member allows them to perform specific actions.
-   * @param {PermissionResolvable[]} permissions The permissions to check for
+   * @param {PermissionResolvable} permissions The permissions to check for
    * @param {boolean} [explicit=false] Whether to require the member to explicitly have the exact permissions
    * @returns {boolean}
    * @deprecated
@@ -335,11 +335,12 @@ class GuildMember {
 
   /**
    * Checks whether the roles of this member allows them to perform specific actions, and lists any missing permissions.
-   * @param {PermissionResolvable[]} permissions The permissions to check for
+   * @param {PermissionResolvable} permissions The permissions to check for
    * @param {boolean} [explicit=false] Whether to require the member to explicitly have the exact permissions
-   * @returns {PermissionResolvable[]}
+   * @returns {PermissionResolvable}
    */
   missingPermissions(permissions, explicit = false) {
+    if (!(permissions instanceof Array)) permissions = [permissions];
     return this.permissions.missing(permissions, explicit);
   }
 
diff --git a/src/structures/PermissionOverwrites.js b/src/structures/PermissionOverwrites.js
index efe9e956b..19630636e 100644
--- a/src/structures/PermissionOverwrites.js
+++ b/src/structures/PermissionOverwrites.js
@@ -1,3 +1,5 @@
+const Permissions = require('../util/Permissions');
+
 /**
  * Represents a permission overwrite for a role or member in a guild channel.
  */
@@ -27,8 +29,29 @@ class PermissionOverwrites {
      */
     this.type = data.type;
 
+    /**
+     * The permissions that are denied for the user or role as a bitfield.
+     * @type {number}
+     */
     this.deny = data.deny;
+
+    /**
+     * The permissions that are allowed for the user or role as a bitfield.
+     * @type {number}
+     */
     this.allow = data.allow;
+
+    /**
+     * The permissions that are denied for the user or role.
+     * @type {Permissions}
+     */
+    this.denied = new Permissions(data.deny).freeze();
+
+    /**
+     * The permissions that are allowed for the user or role.
+     * @type {Permissions}
+     */
+    this.allowed = new Permissions(data.allow).freeze();
   }
 
   /**
diff --git a/src/structures/Role.js b/src/structures/Role.js
index 389e96949..056cf98fd 100644
--- a/src/structures/Role.js
+++ b/src/structures/Role.js
@@ -153,7 +153,7 @@ class Role {
 
   /**
    * Checks if the role has a permission.
-   * @param {PermissionResolvable|PermissionResolvable[]} permission Permission(s) to check for
+   * @param {PermissionResolvable} permission Permission(s) to check for
    * @param {boolean} [explicit=false] Whether to require the role to explicitly have the exact permission
    * **(deprecated)**
    * @param {boolean} [checkAdmin] Whether to allow the administrator permission to override
@@ -175,7 +175,7 @@ class Role {
 
   /**
    * Checks if the role has all specified permissions.
-   * @param {PermissionResolvable[]} permissions The permissions to check for
+   * @param {PermissionResolvable} permissions The permissions to check for
    * @param {boolean} [explicit=false] Whether to require the role to explicitly have the exact permissions
    * @returns {boolean}
    * @deprecated
@@ -201,7 +201,7 @@ class Role {
    * @property {ColorResolvable} [color] The color of the role, either a hex string or a base 10 number
    * @property {boolean} [hoist] Whether or not the role should be hoisted
    * @property {number} [position] The position of the role
-   * @property {PermissionResolvable[]|number} [permissions] The permissions of the role
+   * @property {PermissionResolvable|number} [permissions] The permissions of the role
    * @property {boolean} [mentionable] Whether or not the role should be mentionable
    */
 
@@ -282,7 +282,7 @@ class Role {
 
   /**
    * Set the permissions of the role.
-   * @param {PermissionResolvable|PermissionResolvable[]} permissions The permissions of the role
+   * @param {PermissionResolvable} permissions The permissions of the role
    * @param {string} [reason] Reason for changing the role's permissions
    * @returns {Promise<Role>}
    * @example
diff --git a/src/structures/shared/resolvePermissions.js b/src/structures/shared/resolvePermissions.js
new file mode 100644
index 000000000..c266d46e2
--- /dev/null
+++ b/src/structures/shared/resolvePermissions.js
@@ -0,0 +1,26 @@
+const Permissions = require('../../util/Permissions');
+const Collection = require('../../util/Collection');
+
+module.exports = function resolvePermissions(overwrites, guild) {
+  if (overwrites instanceof Collection || overwrites instanceof Array) {
+    overwrites = overwrites.map(overwrite => {
+      const role = this.client.resolver.resolveRole(guild, overwrite.id);
+      if (role) {
+        overwrite.id = role.id;
+        overwrite.type = 'role';
+      } else {
+        overwrite.id = this.client.resolver.resolveUserID(overwrite.id);
+        overwrite.type = 'member';
+      }
+
+      return {
+        allow: Permissions.resolve(overwrite.allow || overwrite.allowed || 0),
+        deny: Permissions.resolve(overwrite.deny || overwrite.denied || 0),
+        type: overwrite.type,
+        id: overwrite.id,
+      };
+    });
+  }
+
+  return overwrites;
+};
diff --git a/src/util/Permissions.js b/src/util/Permissions.js
index 4ad64d524..901bed312 100644
--- a/src/util/Permissions.js
+++ b/src/util/Permissions.js
@@ -9,7 +9,7 @@ const util = require('util');
 class Permissions {
   /**
    * @param {GuildMember} [member] Member the permissions are for **(deprecated)**
-   * @param {number|PermissionResolvable[]} permissions Permissions or bitfield to read from
+   * @param {number|PermissionResolvable} permissions Permissions or bitfield to read from
    */
   constructor(member, permissions) {
     permissions = typeof member === 'object' && !(member instanceof Array) ? permissions : member;
@@ -53,7 +53,7 @@ class Permissions {
 
   /**
    * Checks whether the bitfield has a permission, or multiple permissions.
-   * @param {PermissionResolvable|PermissionResolvable[]} permission Permission(s) to check for
+   * @param {PermissionResolvable} permission Permission(s) to check for
    * @param {boolean} [checkAdmin=true] Whether to allow the administrator permission to override
    * @returns {boolean}
    */
@@ -66,11 +66,12 @@ class Permissions {
 
   /**
    * Gets all given permissions that are missing from the bitfield.
-   * @param {PermissionResolvable[]} permissions Permissions to check for
+   * @param {PermissionResolvable} permissions Permissions to check for
    * @param {boolean} [checkAdmin=true] Whether to allow the administrator permission to override
-   * @returns {PermissionResolvable[]}
+   * @returns {PermissionResolvable}
    */
   missing(permissions, checkAdmin = true) {
+    if (!(permissions instanceof Array)) permissions = [permissions];
     return permissions.filter(p => !this.has(p, checkAdmin));
   }
 
@@ -128,7 +129,7 @@ class Permissions {
 
   /**
    * Checks whether the user has all specified permissions.
-   * @param {PermissionResolvable[]} permissions The permissions to check for
+   * @param {PermissionResolvable} permissions The permissions to check for
    * @param {boolean} [explicit=false] Whether to require the user to explicitly have the exact permissions
    * @returns {boolean}
    * @see {@link Permissions#has}
@@ -140,9 +141,9 @@ class Permissions {
 
   /**
    * Checks whether the user has all specified permissions, and lists any missing permissions.
-   * @param {PermissionResolvable[]} permissions The permissions to check for
+   * @param {PermissionResolvable} permissions The permissions to check for
    * @param {boolean} [explicit=false] Whether to require the user to explicitly have the exact permissions
-   * @returns {PermissionResolvable[]}
+   * @returns {PermissionResolvable}
    * @see {@link Permissions#missing}
    * @deprecated
    */
@@ -150,6 +151,14 @@ class Permissions {
     return this.missing(permissions, !explicit);
   }
 
+  /**
+   * Freezes these permissions, making them immutable.
+   * @returns {Permissions} These permissions
+   */
+  freeze() {
+    return Object.freeze(this);
+  }
+
   valueOf() {
     return this.bitfield;
   }
@@ -158,12 +167,12 @@ class Permissions {
    * Data that can be resolved to give a permission number. This can be:
    * * A string (see {@link Permissions.FLAGS})
    * * A permission number
-   * @typedef {string|number} PermissionResolvable
+   * @typedef {string|number|Permissions|PermissionResolvable[]} PermissionResolvable
    */
 
   /**
    * Resolves permissions to their numeric form.
-   * @param {PermissionResolvable|PermissionResolvable[]} permission - Permission(s) to resolve
+   * @param {PermissionResolvable} permission - Permission(s) to resolve
    * @returns {number}
    */
   static resolve(permission) {