diff --git a/doc/api/worker_threads.md b/doc/api/worker_threads.md
index af01ed7f7fba0b..b1402d66e1bf33 100644
--- a/doc/api/worker_threads.md
+++ b/doc/api/worker_threads.md
@@ -162,7 +162,7 @@ When this function is used, no `'message'` event will be emitted and the
 added: v13.2.0
 -->
 
-* {Object|undefined}
+* {Object}
   * `maxYoungGenerationSizeMb` {number}
   * `maxOldGenerationSizeMb` {number}
   * `codeRangeSizeMb` {number}