diff --git a/src/display/api.js b/src/display/api.js
index 012e45a63..5128316fb 100644
--- a/src/display/api.js
+++ b/src/display/api.js
@@ -848,8 +848,8 @@ class PDFDocumentProxy {
   }
 
   /**
-   * @type {Array<string, string|null>} A (not guaranteed to be) unique ID to
-   *   identify the PDF document.
+   * @type {Array<string | null>} A (not guaranteed to be) unique ID to identify
+   *   the PDF document.
    *   NOTE: The first element will always be defined for all PDF documents,
    *   whereas the second element is only defined for *modified* PDF documents.
    */