diff --git a/src/ol/layer/BaseImage.js b/src/ol/layer/BaseImage.js
index 10a3ad09ec..9183382986 100644
--- a/src/ol/layer/BaseImage.js
+++ b/src/ol/layer/BaseImage.js
@@ -34,6 +34,7 @@ import Layer from './Layer.js';
  * property on the layer object; for example, setting `title: 'My Title'` in the
  * options means that `title` is observable, and has get/set accessors.
  *
+ * @extends {Layer<import("../source/Image.js").default>}
  * @api
  */
 class BaseImageLayer extends Layer {
@@ -48,12 +49,4 @@ class BaseImageLayer extends Layer {
 
 }
 
-
-/**
- * Return the associated {@link module:ol/source/Image source} of the image layer.
- * @function
- * @return {import("../source/Image.js").default} Source.
- * @api
- */
-BaseImageLayer.prototype.getSource;
 export default BaseImageLayer;
diff --git a/src/ol/layer/BaseTile.js b/src/ol/layer/BaseTile.js
index efeea306a6..0bbfe1c346 100644
--- a/src/ol/layer/BaseTile.js
+++ b/src/ol/layer/BaseTile.js
@@ -39,6 +39,7 @@ import {assign} from '../obj.js';
  * property on the layer object; for example, setting `title: 'My Title'` in the
  * options means that `title` is observable, and has get/set accessors.
  *
+ * @extends {Layer<import("../source/Tile.js").default>}
  * @api
  */
 class BaseTileLayer extends Layer {
@@ -102,13 +103,4 @@ class BaseTileLayer extends Layer {
 }
 
 
-/**
- * Return the associated {@link module:ol/source/Tile tilesource} of the layer.
- * @function
- * @return {import("../source/Tile.js").default} Source.
- * @api
- */
-BaseTileLayer.prototype.getSource;
-
-
 export default BaseTileLayer;
diff --git a/src/ol/layer/BaseVector.js b/src/ol/layer/BaseVector.js
index 6498e00e92..7df1fe9bf3 100644
--- a/src/ol/layer/BaseVector.js
+++ b/src/ol/layer/BaseVector.js
@@ -61,6 +61,8 @@ const Property = {
  * property on the layer object; for example, setting `title: 'My Title'` in the
  * options means that `title` is observable, and has get/set accessors.
  *
+ * @template {import("../source/Vector.js").default|import("../source/VectorTile.js").default} VectorSourceType
+ * @extends {Layer<VectorSourceType>}
  * @api
  */
 class BaseVectorLayer extends Layer {
@@ -219,13 +221,4 @@ class BaseVectorLayer extends Layer {
 }
 
 
-/**
- * Return the associated {@link module:ol/source/Vector vectorsource} of the layer.
- * @function
- * @return {import("../source/Vector.js").default} Source.
- * @api
- */
-BaseVectorLayer.prototype.getSource;
-
-
 export default BaseVectorLayer;
diff --git a/src/ol/layer/Layer.js b/src/ol/layer/Layer.js
index c3fb6a772c..7981a0f288 100644
--- a/src/ol/layer/Layer.js
+++ b/src/ol/layer/Layer.js
@@ -62,6 +62,8 @@ import SourceState from '../source/State.js';
  *
  * @fires import("../render/Event.js").RenderEvent#prerender
  * @fires import("../render/Event.js").RenderEvent#postrender
+ *
+ * @template {import("../source/Source.js").default} SourceType
  */
 class Layer extends BaseLayer {
   /**
@@ -106,7 +108,7 @@ class Layer extends BaseLayer {
       getChangeEventType(LayerProperty.SOURCE),
       this.handleSourcePropertyChange_, this);
 
-    const source = options.source ? options.source : null;
+    const source = options.source ? /** @type {SourceType} */ (options.source) : null;
     this.setSource(source);
   }
 
@@ -130,15 +132,12 @@ class Layer extends BaseLayer {
 
   /**
    * Get the layer source.
-   * @return {import("../source/Source.js").default} The layer source (or `null` if not yet set).
+   * @return {SourceType} The layer source (or `null` if not yet set).
    * @observable
    * @api
    */
   getSource() {
-    const source = this.get(LayerProperty.SOURCE);
-    return (
-      /** @type {import("../source/Source.js").default} */ (source) || null
-    );
+    return /** @type {SourceType} */ (this.get(LayerProperty.SOURCE)) || null;
   }
 
   /**
@@ -227,7 +226,7 @@ class Layer extends BaseLayer {
 
   /**
    * Set the layer source.
-   * @param {import("../source/Source.js").default} source The layer source.
+   * @param {SourceType} source The layer source.
    * @observable
    * @api
    */
diff --git a/src/ol/layer/Vector.js b/src/ol/layer/Vector.js
index 0456b04ea0..46086a490b 100644
--- a/src/ol/layer/Vector.js
+++ b/src/ol/layer/Vector.js
@@ -17,6 +17,7 @@ import CanvasVectorLayerRenderer from '../renderer/canvas/VectorLayer.js';
  * property on the layer object; for example, setting `title: 'My Title'` in the
  * options means that `title` is observable, and has get/set accessors.
  *
+ * @extends {BaseVectorLayer<import("../source/Vector.js").default>}
  * @api
  */
 class VectorLayer extends BaseVectorLayer {
diff --git a/src/ol/layer/VectorTile.js b/src/ol/layer/VectorTile.js
index 5ebf976173..900fb4fb20 100644
--- a/src/ol/layer/VectorTile.js
+++ b/src/ol/layer/VectorTile.js
@@ -70,6 +70,7 @@ import {assign} from '../obj.js';
  * options means that `title` is observable, and has get/set accessors.
  *
  * @param {Options=} opt_options Options.
+ * @extends {BaseVectorLayer<import("../source/VectorTile.js").default>}
  * @api
  */
 class VectorTileLayer extends BaseVectorLayer {
@@ -165,11 +166,4 @@ class VectorTileLayer extends BaseVectorLayer {
 }
 
 
-/**
- * Return the associated {@link module:ol/source/VectorTile vectortilesource} of the layer.
- * @function
- * @return {import("../source/VectorTile.js").default} Source.
- * @api
- */
-VectorTileLayer.prototype.getSource;
 export default VectorTileLayer;