diff --git a/src/ol/source/ImageWMS.js b/src/ol/source/ImageWMS.js
index d33edec1b9..250d460d37 100644
--- a/src/ol/source/ImageWMS.js
+++ b/src/ol/source/ImageWMS.js
@@ -26,7 +26,7 @@ import {appendParams} from '../uri.js';
  * {@link https://developer.mozilla.org/en-US/docs/Web/HTML/CORS_enabled_image} for more detail.
  * @property {boolean} [hidpi=true] Use the `ol.Map#pixelRatio` value when requesting
  * the image from the remote server.
- * @property {ol.source.WMSServerType|string} [serverType=undefined] The type of
+ * @property {ol.source.WMSServerType|string} [serverType] The type of
  * the remote WMS server: `mapserver`, `geoserver` or `qgis`. Only needed if `hidpi` is `true`.
  * @property {ol.ImageLoadFunctionType} [imageLoadFunction] Optional function to load an image given a URL.
  * @property {Object.<string,*>} params WMS request parameters.
diff --git a/src/ol/source/Tile.js b/src/ol/source/Tile.js
index 8d0ad4b727..0b54b5ad29 100644
--- a/src/ol/source/Tile.js
+++ b/src/ol/source/Tile.js
@@ -36,7 +36,7 @@ import {wrapX, getForProjection as getTileGridForProjection} from '../tilegrid.j
  * @constructor
  * @abstract
  * @extends {ol.source.Source}
- * @param {module:ol/source/SourceTile~Options=} options SourceTile source options.
+ * @param {module:ol/source/Tile~Options=} options SourceTile source options.
  * @api
  */
 const TileSource = function(options) {
diff --git a/src/ol/source/TileImage.js b/src/ol/source/TileImage.js
index 68b81ad6b4..a7da58e6e6 100644
--- a/src/ol/source/TileImage.js
+++ b/src/ol/source/TileImage.js
@@ -47,7 +47,7 @@ import {getForProjection as getTileGridForProjection} from '../tilegrid.js';
  * A `{?-?}` template pattern, for example `subdomain{a-f}.domain.com`, may be
  * used instead of defining each one separately in the `urls` option.
  * @property {Array.<string>} [urls] An array of URL templates.
- * @property {boolean} [wrapX=undefined] Whether to wrap the world horizontally. The default, is to
+ * @property {boolean} [wrapX] Whether to wrap the world horizontally. The default, is to
  * request out-of-bounds tiles from the server. When set to `false`, only one
  * world will be rendered. When set to `true`, tiles will be requested for one
  * world only, but they will be wrapped horizontally to render multiple worlds.
diff --git a/src/ol/source/TileWMS.js b/src/ol/source/TileWMS.js
index 73210f11e3..a31833a63b 100644
--- a/src/ol/source/TileWMS.js
+++ b/src/ol/source/TileWMS.js
@@ -52,7 +52,7 @@ import {appendParams} from '../uri.js';
  * If this is not defined, a default grid will be used: if there is a projection
  * extent, the grid will be based on that; if not, a grid based on a global
  * extent with origin at 0,0 will be used..
- * @property {ol.source.WMSServerType|string} [serverType=undefined]
+ * @property {ol.source.WMSServerType|string} [serverType]
  * The type of the remote WMS server. Currently only used when `hidpi` is
  * `true`.
  * @property {ol.TileLoadFunctionType} [tileLoadFunction] Optional function to load a tile given a URL. The default is
diff --git a/src/ol/source/Vector.js b/src/ol/source/Vector.js
index bd4eb5aaa9..217d2e9a80 100644
--- a/src/ol/source/Vector.js
+++ b/src/ol/source/Vector.js
@@ -54,7 +54,7 @@ inherits(VectorSourceEvent, Event);
  * @property {Array.<module:ol/Feature~Feature>|ol.Collection.<module:ol/Feature~Feature>} [features]
  * Features. If provided as {@link ol.Collection}, the features in the source
  * and the collection will stay in sync.
- * @property {ol.format.Feature} [format=undefined] The feature format used by the XHR
+ * @property {ol.format.Feature} [format] The feature format used by the XHR
  * feature loader when `url` is set. Required if `url` is set, otherwise ignored.
  * @property {module:ol/Feature~FeatureLoader} [loader]
  * The loader function used to load features, from a remote source for example.
diff --git a/src/ol/source/WMTS.js b/src/ol/source/WMTS.js
index 983693589a..e1d43cdea5 100644
--- a/src/ol/source/WMTS.js
+++ b/src/ol/source/WMTS.js
@@ -80,7 +80,7 @@ import {appendParams} from '../uri.js';
  * If this is not defined, a default grid will be used: if there is a projection
  * extent, the grid will be based on that; if not, a grid based on a global
  * extent with origin at 0,0 will be used..
- * @property {ol.source.WMSServerType|string} [serverType=undefined]
+ * @property {ol.source.WMSServerType|string} [serverType]
  * The type of the remote WMS server. Currently only used when `hidpi` is
  * `true`.
  * @property {string} [url] WMS service URL.