diff --git a/src/ol/tilegrid/TileGrid.js b/src/ol/tilegrid/TileGrid.js
index 9b391c8725..a375e47749 100644
--- a/src/ol/tilegrid/TileGrid.js
+++ b/src/ol/tilegrid/TileGrid.js
@@ -237,6 +237,7 @@ class TileGrid {
   /**
    * Get the extent for this tile grid, if it was configured.
    * @return {import("../extent.js").Extent} Extent.
+   * @api
    */
   getExtent() {
     return this.extent_;