diff --git a/packages/discord.js/src/structures/ThreadChannel.js b/packages/discord.js/src/structures/ThreadChannel.js
index e317c3836..fb69bf1e5 100644
--- a/packages/discord.js/src/structures/ThreadChannel.js
+++ b/packages/discord.js/src/structures/ThreadChannel.js
@@ -103,12 +103,8 @@ class ThreadChannel extends Channel {
       this.archiveTimestamp = Date.parse(data.thread_metadata.archive_timestamp);
 
       if ('create_timestamp' in data.thread_metadata) {
-        /**
-         * The timestamp when this thread was created. This isn't available for threads
-         * created before 2022-01-09
-         * @type {?number}
-         */
-        this.createdTimestamp = Date.parse(data.thread_metadata.create_timestamp);
+        // Note: this is needed because we can't assign directly to getters
+        this._createdTimestamp = Date.parse(data.thread_metadata.create_timestamp);
       }
     } else {
       this.locked ??= null;
@@ -118,7 +114,7 @@ class ThreadChannel extends Channel {
       this.invitable ??= null;
     }
 
-    this.createdTimestamp ??= this.type === ChannelType.GuildPrivateThread ? super.createdTimestamp : null;
+    this._createdTimestamp ??= this.type === ChannelType.GuildPrivateThread ? super.createdTimestamp : null;
 
     if ('owner_id' in data) {
       /**
@@ -188,6 +184,16 @@ class ThreadChannel extends Channel {
     if (data.messages) for (const message of data.messages) this.messages._add(message);
   }
 
+  /**
+   * The timestamp when this thread was created. This isn't available for threads
+   * created before 2022-01-09
+   * @type {?number}
+   * @readonly
+   */
+  get createdTimestamp() {
+    return this._createdTimestamp;
+  }
+
   /**
    * A collection of associated guild member objects of this thread's members
    * @type {Collection<Snowflake, GuildMember>}
diff --git a/packages/discord.js/typings/index.d.ts b/packages/discord.js/typings/index.d.ts
index cfd13f52b..43e878a7d 100644
--- a/packages/discord.js/typings/index.d.ts
+++ b/packages/discord.js/typings/index.d.ts
@@ -2193,7 +2193,8 @@ export class ThreadChannel extends TextBasedChannelMixin(Channel) {
   public readonly archivedAt: Date | null;
   public archiveTimestamp: number | null;
   public readonly createdAt: Date | null;
-  public createdTimestamp: number | null;
+  private _createdTimestamp: number | null;
+  public readonly createdTimestamp: number | null;
   public autoArchiveDuration: ThreadAutoArchiveDuration | null;
   public readonly editable: boolean;
   public guild: Guild;