diff --git a/externs/olx.js b/externs/olx.js
index 55387980ba..7de64fb3e1 100644
--- a/externs/olx.js
+++ b/externs/olx.js
@@ -649,114 +649,6 @@ olx.style.StyleOptions.prototype.text;
olx.style.StyleOptions.prototype.zIndex;
-/**
- * @typedef {{extent: (ol.Extent|undefined),
- * origin: (ol.Coordinate|undefined),
- * origins: (Array.
|undefined),
- * resolutions: !Array.,
- * matrixIds: !Array.,
- * sizes: (Array.|undefined),
- * tileSize: (number|ol.Size|undefined),
- * tileSizes: (Array.|undefined)}}
- */
-olx.tilegrid.WMTSOptions;
-
-
-/**
- * Extent for the tile grid. No tiles outside this extent will be requested by
- * {@link ol.source.Tile} sources. When no `origin` or `origins` are
- * configured, the `origin` will be set to the top-left corner of the extent.
- * @type {ol.Extent|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.extent;
-
-
-/**
- * The tile grid origin, i.e. where the `x` and `y` axes meet (`[z, 0, 0]`).
- * Tile coordinates increase left to right and upwards. If not specified,
- * `extent` or `origins` must be provided.
- * @type {ol.Coordinate|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.origin;
-
-
-/**
- * Tile grid origins, i.e. where the `x` and `y` axes meet (`[z, 0, 0]`), for
- * each zoom level. If given, the array length should match the length of the
- * `resolutions` array, i.e. each resolution can have a different origin. Tile
- * coordinates increase left to right and upwards. If not specified, `extent` or
- * `origin` must be provided.
- * @type {Array.|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.origins;
-
-
-/**
- * Resolutions. The array index of each resolution needs to match the zoom
- * level. This means that even if a `minZoom` is configured, the resolutions
- * array will have a length of `maxZoom + 1`
- * @type {!Array.}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.resolutions;
-
-
-/**
- * matrix IDs. The length of this array needs to match the length of the
- * `resolutions` array.
- * @type {!Array.}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.matrixIds;
-
-
-/**
- * Number of tile rows and columns of the grid for each zoom level. The values
- * here are the `TileMatrixWidth` and `TileMatrixHeight` advertised in the
- * GetCapabilities response of the WMTS, and define the grid's extent together
- * with the `origin`. An `extent` can be configured in addition, and will
- * further limit the extent for which tile requests are made by sources. Note
- * that when the top-left corner of the `extent` is used as `origin` or
- * `origins`, then the `y` value must be negative because OpenLayers tile
- * coordinates increase upwards.
- * @type {Array.|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.sizes;
-
-
-/**
- * Tile size.
- * @type {number|ol.Size|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.tileSize;
-
-
-/**
- * Tile sizes. The length of this array needs to match the length of the
- * `resolutions` array.
- * @type {Array.|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.tileSizes;
-
-
-/**
- * Number of tile columns that cover the grid's extent for each zoom level. Only
- * required when used with a source that has `wrapX` set to `true`, and only
- * when the grid's origin differs from the one of the projection's extent. The
- * array length has to match the length of the `resolutions` array, i.e. each
- * resolution will have a matching entry here.
- * @type {Array.|undefined}
- * @api
- */
-olx.tilegrid.WMTSOptions.prototype.widths;
-
-
/**
* @typedef {{extent: (ol.Extent|undefined),
* maxZoom: (number|undefined),
diff --git a/src/ol/tilegrid/WMTS.js b/src/ol/tilegrid/WMTS.js
index 6f85132fde..2f20824b29 100644
--- a/src/ol/tilegrid/WMTS.js
+++ b/src/ol/tilegrid/WMTS.js
@@ -6,13 +6,52 @@ import {find} from '../array.js';
import {get as getProjection} from '../proj.js';
import TileGrid from '../tilegrid/TileGrid.js';
+
+/**
+ * @typedef {Object} Options
+ * @property {module:ol/extent~Extent} [extent] Extent for the tile grid. No tiles
+ * outside this extent will be requested by {@link module:ol/source/Tile} sources.
+ * When no `origin` or `origins` are configured, the `origin` will be set to the
+ * top-left corner of the extent.
+ * @property {module:ol/coordinate~Coordinate} [origin] The tile grid origin, i.e.
+ * where the `x` and `y` axes meet (`[z, 0, 0]`). Tile coordinates increase left
+ * to right and upwards. If not specified, `extent` or `origins` must be provided.
+ * @property {Array.} [origins] Tile grid origins,
+ * i.e. where the `x` and `y` axes meet (`[z, 0, 0]`), for each zoom level. If
+ * given, the array length should match the length of the `resolutions` array, i.e.
+ * each resolution can have a different origin. Tile coordinates increase left to
+ * right and upwards. If not specified, `extent` or `origin` must be provided.
+ * @property {!Array.} resolutions Resolutions. The array index of each
+ * resolution needs to match the zoom level. This means that even if a `minZoom`
+ * is configured, the resolutions array will have a length of `maxZoom + 1`
+ * @property {!Array.} matrixIds matrix IDs. The length of this array needs
+ * to match the length of the `resolutions` array.
+ * @property {Array.} [sizes] Number of tile rows and columns
+ * of the grid for each zoom level. The values here are the `TileMatrixWidth` and
+ * `TileMatrixHeight` advertised in the GetCapabilities response of the WMTS, and
+ * define the grid's extent together with the `origin`.
+ * An `extent` can be configured in addition, and will further limit the extent for
+ * which tile requests are made by sources. Note that when the top-left corner of
+ * the `extent` is used as `origin` or `origins`, then the `y` value must be
+ * negative because OpenLayers tile coordinates increase upwards.
+ * @property {number|module:ol/size~Size} [tileSize] Tile size.
+ * @property {Array.} [tileSizes] Tile sizes. The length of
+ * this array needs to match the length of the `resolutions` array.
+ * @property {Array.} [widths] Number of tile columns that cover the grid's
+ * extent for each zoom level. Only required when used with a source that has `wrapX`
+ * set to `true`, and only when the grid's origin differs from the one of the
+ * projection's extent. The array length has to match the length of the `resolutions`
+ * array, i.e. each resolution will have a matching entry here.
+ */
+
+
/**
* @classdesc
* Set the grid pattern for sources accessing WMTS tiled-image servers.
*
* @constructor
* @extends {module:ol/tilegrid/TileGrid~TileGrid}
- * @param {olx.tilegrid.WMTSOptions} options WMTS options.
+ * @param {module:ol/tilegrid/WMTS~Options} options WMTS options.
* @struct
* @api
*/