diff --git a/src/ol/transform.js b/src/ol/transform.js
index 3eb9ecd6ac..a113e3e106 100644
--- a/src/ol/transform.js
+++ b/src/ol/transform.js
@@ -8,6 +8,7 @@ import {assert} from './asserts.js';
  * An array representing an affine 2d transformation for use with
  * {@link module:ol/transform} functions. The array has 6 elements.
  * @typedef {!Array<number>} Transform
+ * @api
  */